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]: Perennial grass takes ____ to five years before it is mature enough to produce adequate seed.\Question: Choose the right answer from options given a) six b) zero c) three d) no
[A]: c


[Q]: Some infected horses show ____ signs and become chronic carriers of the disease.\Question: Choose the right answer from options given a) nine b) six c) four d) no
[A]: d


[Q]: Glial cells multiply dramatically from fetal age ____ months to the child's second birthday.\Question: Choose the right answer from options given a) six b) one c) four d) eight
[A]:
c