Given a sentence with a missing word, pick the answer option that best fills out the missing word in the sentence. Indicate each answer with its index ('a', 'b', 'c', 'd').

[Q]: Midrange drivers are used in multi-way speakers with ____ or more driver sizes.\Question: Choose the right answer from options given a) one b) five c) four d) three
[A]: d


[Q]: Astronauts sleep only ____ hours each night, on average.\Question: Choose the right answer from options given a) six b) one c) four d) seven
[A]: a


[Q]: Most leaflets have one to ____ coarse teeth near their base.\Question: Choose the right answer from options given a) four b) ten c) two d) three
[A]:
d