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
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Q: Elephants give birth to one calf every ____ to nine years on average.\Question: Choose the right answer from options given a) no b) four c) three d) seven

A: b
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Q: Rabbits reach sexual maturity between ____ and six months of age.\Question: Choose the right answer from options given a) five b) eight c) nine d) three

A:
d
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