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: Healthcare providers diagnose ____ general types of insomnia.\Question: Choose the right answer from options given a) two b) eight c) one d) three

A: a
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Q: Alleles fall into ____ classes based on somatic, gonadal and dauer phenotypes.\Question: Choose the right answer from options given a) ten b) six c) eight d) no

A: b
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Q: Elephants have four molars, which are replaced five times, for a total of ____ sets in a lifetime.\Question: Choose the right answer from options given a) three b) six c) eight d) zero

A:
b
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