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:
Banks hold ____ excess reserves and the public holds no currency.\Question: Choose the right answer from options given a) two b) seven c) ten d) no

Ex Output:
d


Ex Input:
Every person is a carrier for about ____ rare genetic conditions.\Question: Choose the right answer from options given a) nine b) ten c) six d) three

Ex Output:
b


Ex Input:
Male cats are fertile from ____ months, and can impregnate up to thirty-two female cats a year.\Question: Choose the right answer from options given a) six b) eight c) one d) zero

Ex Output:

a