Please answer the following question: Information:  - Sherborn is a town in Middlesex County, Massachusetts, United States. It is in area code 508 and has the ZIP code 01770. As of the 2010 U.S. Census, the town population was 4,119.  - Massachusetts ; officially the Commonwealth of Massachusetts, is the most populous state in the New England region of the northeastern United States. It is bordered by the Atlantic Ocean to the east, the states of Connecticut and Rhode Island to the south, New Hampshire and Vermont to the north, and New York to the west. The state is named for the Massachusett tribe, which once inhabited the area. The capital of Massachusetts and the most populous city in New England is Boston. Over 80% of Massachusetts' population lives in the Greater Boston metropolitan area, a region influential upon American history, academia, and industry. Originally dependent on agriculture, fishing and trade, Massachusetts was transformed into a manufacturing center during the Industrial Revolution. During the 20th century, Massachusetts' economy shifted from manufacturing to services. Modern Massachusetts is a global leader in biotechnology, engineering, higher education, finance, and maritime trade.  - ZIP Codes are a system of postal codes used by the United States Postal Service (USPS) since 1963. The term "ZIP", an acronym for Zone Improvement Plan, was chosen to suggest that the mail travels more efficiently, and therefore more quickly (zipping along), when senders use the code in the postal address. The basic format consists of five numerical digits. An extended ZIP+4 code, introduced in 1983, includes the five digits of the ZIP Code, a hyphen, and four additional digits that determine a more specific location within a given ZIP Code.  - A roof is part of a building envelope. It is the covering on the uppermost part of a building or shelter which provides protection from animals and weather, notably rain or snow, but also heat, wind and sunlight. The word also denotes the framing or structure which supports that covering.  - The Joseph Twitchell House is a historic house at 32 Pleasant Street in Sherborn , Massachusetts . It was built circa 1710 , or possibly 1690 , with a north wing dating from the early 1800s . It is one of a small number of houses in Sherborn that have elements that may date to the 17th century . It is a 2 - 1/2 story wood frame saltbox house , 3 wide bays , with a massive central chimney , side gable roof , and clapboard siding . Inside it is laid out as a central hall , one room on either side , and lean - to at the rear . The Georgian front door is flanked by Doric pilasters and topped by a multi-pane transom and entablature . The house was listed on the National Register of Historic Places in 1986 .  - Wood is a porous and fibrous structural tissue found in the stems and roots of trees, and other woody plants. It is an organic material, a natural composite of cellulose fibers which are strong in tension embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber.  - A chimney is a structure that provides ventilation for hot flue gases or smoke from a boiler, stove, furnace or fireplace to the outside atmosphere. Chimneys are typically vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the combustion in what is known as the stack, or chimney, effect. The space inside a chimney is called a "flue". Chimneys may be found in buildings, steam locomotives and ships. In the United States, the term smokestack (colloquially, stack) is also used when referring to locomotive chimneys or ship chimneys, and the term funnel can also be used.  - A saltbox house is a traditional New England style of house with a long, pitched roof that slopes down to the back, generally a wooden frame house. A saltbox has just one story in the back and two stories in the front. The flat front and central chimney are recognizable features, but the asymmetry of the unequal sides and the long, low rear roof line are the most distinctive features of a saltbox, which takes its name from its resemblance to a wooden lidded box in which salt was once kept.  - New England is a geographical region comprising six states of the northeast United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York to the west and south, and the Canadian provinces of New Brunswick and Quebec to the northeast and north, respectively. The Atlantic Ocean is to the east and southeast, and Long Island Sound is to the south. Boston is its largest city. Its largest metropolitan area is Greater Boston, which also includes Worcester (the second-largest city in New England), Manchester (the largest city in New Hampshire), and Providence (the capital and largest city of Rhode Island), with nearly a third of the entire region's population.    After reading the paragraphs above, we are interested in knowing the entity with which 'joseph twitchell house' exhibits the relationship of 'instance of'. Find the answer from the choices below.  Choices: - area  - atmosphere  - box  - building  - capital  - century  - chimney  - city  - code  - combustion  - county  - drawing  - education  - england  - format  - front  - function  - furnace  - history  - house  - location  - mail  - material  - may  - metropolitan  - name  - ocean  - plan  - population  - roof  - salt  - saltbox  - service  - ship  - snow  - space  - stack  - state  - structure  - system  - tissue  - town  - tree  - tribe  - two  - water  - weather  - word  - zip code
A:
building