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: Many comets have ____ tails.\Question: Choose the right answer from options given a) two b) six c) three d) one

A: a
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Q: Many tortoises can retract their head, their ____ limbs and tail into the shell for protection.\Question: Choose the right answer from options given a) no b) one c) two d) four

A: d
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Q: American anthropology has ____ broad subfields.\Question: Choose the right answer from options given a) five b) four c) two d) ten

A:
b
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