Q: Question: "what is been discussed?"  Context: "Both private individuals and large production companies have used YouTube to grow audiences. Independent content creators have built grassroots followings numbering in the thousands at very little cost or effort, while mass retail and radio promotion proved problematic. Concurrently, old media celebrities moved into the website at the invitation of a YouTube management that witnessed early content creators accruing substantial followings, and perceived audience sizes potentially larger than that attainable by television. While YouTube's revenue-sharing "Partner Program" made it possible to earn a substantial living as a video producer—its top five hundred partners each earning more than $100,000 annually and its ten highest-earning channels grossing from $2.5 million to $12 million—in 2012 CMU business editor characterized YouTube as "a free-to-use... promotional platform for the music labels". In 2013 Forbes' Katheryn Thayer asserted that digital-era artists' work must not only be of high quality, but must elicit reactions on the YouTube platform and social media. In 2013, videos of the 2.5% of artists categorized as "mega", "mainstream" and "mid-sized" received 90.3% of the relevant views on YouTube and Vevo. By early 2013 Billboard had announced that it was factoring YouTube streaming data into calculation of the Billboard Hot 100 and related genre charts."  Answer:
A: YouTube

Q: Question: "Who is the third composer listed that composed the Gregorian chant music"  Context: "The Roman Missal and the Roman Rite Liturgy of the Hours naturally includes references to Mary's immaculate conception in the feast of the Immaculate Conception. An example is the antiphon that begins: "Tota pulchra es, Maria, et macula originalis non est in te" (You are all beautiful, Mary, and the original stain [of sin] is not in you. Your clothing is white as snow, and your face is like the sun. You are all beautiful, Mary, and the original stain [of sin] is not in you. You are the glory of Jerusalem, you are the joy of Israel, you give honour to our people. You are all beautiful, Mary.) On the basis of the original Gregorian chant music, polyphonic settings have been composed by Anton Bruckner, Pablo Casals, Maurice Duruflé, Grzegorz Gerwazy Gorczycki, no:Ola Gjeilo, José Maurício Nunes Garcia, and Nikolaus Schapfl,"  Answer:
A: Maurice Duruflé

Q: Question: "Why is the nickname possibly not very valid?"  Context: "Whereas the chromosomes of prokaryotes are relatively gene-dense, those of eukaryotes often contain regions of DNA that serve no obvious function. Simple single-celled eukaryotes have relatively small amounts of such DNA, whereas the genomes of complex multicellular organisms, including humans, contain an absolute majority of DNA without an identified function. This DNA has often been referred to as "junk DNA". However, more recent analyses suggest that, although protein-coding DNA makes up barely 2% of the human genome, about 80% of the bases in the genome may be expressed, so the term "junk DNA" may be a misnomer."  Answer:
A: about 80% of the bases in the genome may be expressed, so the term "junk DNA" may be a misnomer

Q: Question: "What is an advantage of testing brain function in animals?"  Context: "Another approach to brain function is to examine the consequences of damage to specific brain areas. Even though it is protected by the skull and meninges, surrounded by cerebrospinal fluid, and isolated from the bloodstream by the blood–brain barrier, the delicate nature of the brain makes it vulnerable to numerous diseases and several types of damage. In humans, the effects of strokes and other types of brain damage have been a key source of information about brain function. Because there is no ability to experimentally control the nature of the damage, however, this information is often difficult to interpret. In animal studies, most commonly involving rats, it is possible to use electrodes or locally injected chemicals to produce precise patterns of damage and then examine the consequences for behavior."  Answer:
A:
it is possible to use electrodes or locally injected chemicals to produce precise patterns of damage