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: Elephants have four molars, which are replaced ____ times, for a total of six sets in a lifetime.\Question: Choose the right answer from options given a) five b) no c) three d) one

A: a
****
Q: Bucks grow antlers each year that reach ____ to six feet in spread.\Question: Choose the right answer from options given a) seven b) one c) three d) five

A: d
****
Q: Otters can stay underwater for more than ____ minutes while they hunt for their prey.\Question: Choose the right answer from options given a) zero b) three c) no d) seven

A:
b
****