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]: Matter exists in ____ forms, solid, fluid and plasma.\Question: Choose the right answer from options given a) ten b) nine c) three d) five
[A]: c


[Q]: Ossification begins up to ____ months before birth.\Question: Choose the right answer from options given a) nine b) seven c) three d) six
[A]: b


[Q]: Voles leave ____ mounds at all behind.\Question: Choose the right answer from options given a) five b) zero c) nine d) no
[A]:
d