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]: Vision problems affect one in ____ school-aged children.\Question: Choose the right answer from options given a) six b) four c) seven d) one
[A]: b


[Q]: Pups remain in the den for about ____ weeks, and are cared for by the entire pack.\Question: Choose the right answer from options given a) ten b) three c) six d) no
[A]: c


[Q]: Captive females begin to mate at ____ or nine years of age.\Question: Choose the right answer from options given a) no b) eight c) nine d) six
[A]:
b