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]: Gestation lasts ____ months, with the birth of a single calf.\Question: Choose the right answer from options given a) three b) one c) six d) eight
[A]: d


[Q]: Children of alcoholics are ____ times more likely than other people to become alcoholics themselves.\Question: Choose the right answer from options given a) zero b) four c) nine d) two
[A]: b


[Q]: Water can exist on the surface of the earth and the air in all ____ states - solid, liquid or gas.\Question: Choose the right answer from options given a) no b) six c) three d) five
[A]:
c