Please answer the following question: Information:  - Acornsoft was the software arm of Acorn Computers, and a major publisher of software for the BBC Micro and Acorn Electron. As well as games, it also produced a large number of educational titles, extra computer languages and business and utility packages  these included word processor "VIEW" and the spreadsheet "ViewSheet" supplied on ROM and cartridge for the BBC Micro/Acorn Electron and included as standard in the BBC Master and Acorn Business Computer.  - Professor Peter D. Killworth (27 March 1946  28 January 2008) was an English scientist known for both his work on oceanography and the study of social networks. A prolific writer, he published more than 160 scientific papers over the course of his career. He was also known for his work as a pioneering author of text interactive fiction games during the early 1980s.  - BBC BASIC is a programming language, developed in 1981 as a native programming language for the MOS Technology 6502 based Acorn BBC Micro home/personal computer, mainly by Sophie Wilson. It is a version of the BASIC programming language adapted for a UK computer literacy project of the BBC.  - The Acorn Electron is a budget version of the BBC Micro educational/home computer made by Acorn Computers Ltd. It has 32 kilobytes of RAM, and its ROM includes BBC BASIC v2 along with its operating system.  - Interactive fiction, often abbreviated IF, is software simulating environments in which players use text commands to control characters and influence the environment. Works in this form can be understood as literary narratives, either in the form of Interactive narratives or Interactive narrations. These works can also be understood as a form of video game, either in the form of an adventure game or role-playing game. In common usage, the term refers to text adventures, a type of adventure game where the entire interface can be "text-only", however, Graphical text adventure games, where the text is accompanied by graphics (still images, animations or video) still fall under the text adventure category if the main way to interact with the game is by typing text. Some users of the term distinguish between interactive fiction, known as "Puzzle-free", that focuses on narrative, and "text adventures" that focus on puzzles.  - Countdown to Doom is a text adventure computer game, more recently termed interactive fiction, written in 1982 by Peter Killworth. Its setting is the planet Doomawangara, which is coyly said to be shortened to "Doom". There are two sequels, "Return to Doom" and "Last Days of Doom".  - Acorn Computers Ltd. was a British computer company established in Cambridge, England, in 1978. The company produced a number of computers which were especially popular in the UK, including the Acorn Electron and the Acorn Archimedes. Acorn's BBC Micro computer dominated the UK educational computer market during the 1980s. It is more known for its computer than for its other products.  - The Acorn Archimedes is a family of personal computers designed by Acorn Computers Ltd in Cambridge, England and sold in the late-1980s to mid-1990s, their first general purpose home computer based on their own ARM architecture (then the CPU and architecture was known as Acorn RISC Machine, or ARM, that later became one of the most widely used CPU architectures in the world, e.g. used in most smartphones). The first Archimedes was launched in 1987.  - The kilobyte is a multiple of the unit byte for digital information. The International System of Units (SI) defines the prefix "kilo" as 1000 (10); therefore one kilobyte is 1000 bytes. The unit symbol for the kilobyte is kB. In information technology, particularly in reference to main memory capacity, "kilobyte" is traditionally used to denote 1024 (2) bytes. This arises from the powers-of-two sizing common to such memory in digital circuitry. In this context, the symbols K and KB are often used when 1024 bytes is meant.   - Oceanography (compound of the Greek words  meaning "ocean" and  meaning "write"), also known as oceanology, is the study of the physical and the biological aspects of the ocean. It is an Earth science covering a wide range of topics, including ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and physical properties within the ocean and across its boundaries. These diverse topics reflect multiple disciplines that oceanographers blend to further knowledge of the world ocean and understanding of processes within: astronomy, biology, chemistry, climatology, geography, geology, hydrology, meteorology and physics. Paleoceanography studies the history of the oceans in the geologic past.  - Castle of Riddles is a text adventure released by Acornsoft for the BBC Micro ( in 1982 ) and Acorn Electron ( 1984 ) home computers . The game was written by Peter Killworth and was one of a series of text adventures written for , or ported to the BBC Micro by the same author ( others including Countdown to Doom and Philosopher 's Quest ) . As with all such games , only text is used . The player must use a simple ' verb - noun ' format ( e.g. ' Go North ' , ' Get lamp ' ) to control the game . Unlike Killworth 's other Acornsoft adventures , Castle of Riddles was not updated and reissued by Topologika so became unavailable after 1985 when Acorn Computers ( parent company of Acornsoft ) pulled out of the games publishing market . Some of the puzzles however were included in the Topologika version of Philosopher 's Quest .  - Home computers were a class of microcomputers entering the market in 1977, and becoming common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user. These computers were a distinct market segment that typically cost much less than business, scientific or engineering-oriented computers of the time such as the IBM PC, and were generally less powerful in terms of memory and expandability. However, a home computer often had better graphics and sound than contemporaneous business computers. Their most common uses were playing video games, but they were also regularly used for word processing, doing homework, and programming.  - Topologika Software Ltd was an independent British publisher of educational software. Established in Stilton, Cambridgeshire in 1983, the company spent most of its life in Penryn, Cornwall before moving to Brighton, Sussex. The company was dissolved at the end of June 2013. Its educational software continues to be sold by distributors REM via , and is still supported by Topologika's founder Brian Kerslake.  - The BBC Microcomputer System, or BBC Micro, is a series of microcomputers and associated peripherals designed and built by the Acorn Computer company for the "BBC Computer Literacy Project", operated by the British Broadcasting Corporation. Designed with an emphasis on education, it was notable for its ruggedness, expandability, and the quality of its operating system. An accompanying 1982 television series ""The Computer Programme"" featuring Chris Serle learning to use the machine was also broadcast on BBC 2.  - The Acorn Business Computer (ABC) was a series of microcomputers announced at the end of 1983 by the British company Acorn Computers. The series of eight computers was aimed at the business, research and further education markets. However, the ABC range was cancelled before any of the models were shipped to customers. The ABC 210 was subsequently relaunched as the Acorn Cambridge Workstation, sold in modest numbers to academic and scientific users.    Given the information above, choose from the list below the object entity that exhibits the relation 'genre' with the subject 'castle of riddles'.  Choices: - adventure  - basic  - chemistry  - education  - educational software  - family  - game  - geography  - graphics  - information  - interactive fiction  - march  - narrative  - research  - science  - study  - technology  - various
Answer:
interactive fiction