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: Some male fish return after just ____ years.\Question: Choose the right answer from options given a) no b) two c) one d) six

A: b
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Q: Most toddlers find it hard to sit still for more than a few seconds, let alone ____ minutes.\Question: Choose the right answer from options given a) no b) three c) four d) zero

A: b
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Q: Natural samarium is a mixture of ____ isotopes, four of which are unstable with long half-lives.\Question: Choose the right answer from options given a) ten b) seven c) zero d) one

A:
b
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