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:
Wolverines reproduce every ____ or three years.\Question: Choose the right answer from options given a) two b) three c) one d) four

Ex Output:
a


Ex Input:
Chinese cuisine has ____ tolerance for animal rights groups.\Question: Choose the right answer from options given a) ten b) zero c) four d) no

Ex Output:
b


Ex Input:
Dairy cows live for ____ generations, calve and produce normal milk on a protein-free diet.\Question: Choose the right answer from options given a) six b) three c) zero d) nine

Ex Output:

a