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]: Most females are sexually mature at about ____ to six years.\Question: Choose the right answer from options given a) eight b) nine c) five d) two
[A]: c


[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]: Quasars are the most energetic and distant of all ____ objects.\Question: Choose the right answer from options given a) five b) three c) one d) no
[A]:
b