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]: Serial transfer is the sequential transmission of the ____ bit-voltages that constitute a byte.\Question: Choose the right answer from options given a) ten b) eight c) two d) four
[A]: b


[Q]: Aridity presents ____ main obstacles to solitary behavior.\Question: Choose the right answer from options given a) no b) three c) two d) five
[A]: c


[Q]: Male mice become imprinted with the odor of littermates during the first ____ weeks of life.\Question: Choose the right answer from options given a) seven b) one c) three d) four
[A]:
c