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:
Cows have four stomachs, and the first ____ yield merchantable tripe.\Question: Choose the right answer from options given a) two b) five c) zero d) three

Ex Output:
d


Ex Input:
Whales are divided into ____ categories, based on their teeth.\Question: Choose the right answer from options given a) two b) four c) nine d) ten

Ex Output:
a


Ex Input:
Parliaments can last ____ years, often last four and a bit.\Question: Choose the right answer from options given a) three b) zero c) six d) five

Ex Output:

d