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]: Ground squirrels breed once a year, averaging ____ to eight per litter.\Question: Choose the right answer from options given a) seven b) one c) six d) ten
[A]: a


[Q]: Conglomerate integration is when ____ apparently unconnected companies merge.\Question: Choose the right answer from options given a) two b) six c) no d) three
[A]: a


[Q]: Breakthrough drugs are by definition rare, ranging from ____ to three per year worldwide.\Question: Choose the right answer from options given a) six b) one c) ten d) eight
[A]:
b