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').

Cows can be up to ____ times more active than normal while in heat.\Question: Choose the right answer from options given a) eight b) nine c) two d) six
a

Oar boats are smaller than motor boats and can accommodate four to ____ people.\Question: Choose the right answer from options given a) zero b) three c) five d) no
c

Captive females begin to mate at eight or ____ years of age.\Question: Choose the right answer from options given a) nine b) six c) no d) five

a