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').

Ex Input:
Phytochemicals are non-nutritive substances, in that they contain ____ vitamins or minerals.\Question: Choose the right answer from options given a) four b) one c) no d) ten

Ex Output:
c


Ex Input:
Some sources claim there are more like ____ million vertebrate animals in zoos.\Question: Choose the right answer from options given a) six b) five c) one d) three

Ex Output:
b


Ex Input:
Rock cavies become sexually mature when they are about ____ to three months old.\Question: Choose the right answer from options given a) nine b) one c) two d) five

Ex Output:

b