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:
Pups remain in the den for about ____ weeks, and are cared for by the entire pack.\Question: Choose the right answer from options given a) ten b) three c) six d) no

Ex Output:
c


Ex Input:
Some sources claim there are more like ____ million vertebrate animals in zoos.\Question: Choose the right answer from options given a) six b) five c) one d) three

Ex Output:
b


Ex Input:
Eschatology is divided into ____ major schools of thoughts.\Question: Choose the right answer from options given a) two b) seven c) three d) nine

Ex Output:

c