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:
Aridity presents ____ main obstacles to solitary behavior.\Question: Choose the right answer from options given a) no b) three c) two d) five

Ex Output:
c


Ex Input:
Children of alcoholics are ____ times more likely than other people to become alcoholics themselves.\Question: Choose the right answer from options given a) zero b) four c) nine d) two

Ex Output:
b


Ex Input:
Circumcisions usually heal within one to ____ weeks.\Question: Choose the right answer from options given a) eight b) nine c) no d) two

Ex Output:

d