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
****
Q: Female cats can go into heat for the first time as early as ____ months of age.\Question: Choose the right answer from options given a) four b) zero c) five d) eight

A: c
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Q: Some plants have ____ or four tunnels per stalk.\Question: Choose the right answer from options given a) one b) three c) no d) four

A:
b
****