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]: Shamrocks can be ____ of four leafs.\Question: Choose the right answer from options given a) six b) seven c) zero d) three
[A]: d


[Q]: Calves remain hidden for much of the time, and are weaned by ____ months of age.\Question: Choose the right answer from options given a) six b) three c) eight d) one
[A]: b


[Q]: Pipelines transport crude oil to refineries, a process that takes ____ days on average.\Question: Choose the right answer from options given a) nine b) six c) ten d) two
[A]:
c