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:
Most people recover in one to ____ months.\Question: Choose the right answer from options given a) no b) three c) seven d) eight

Ex Output:
b


Ex Input:
Krill employ ____ types of spawning mechanism.\Question: Choose the right answer from options given a) ten b) six c) four d) two

Ex Output:

d