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:
Cats can harbor a heartworm infection at any age from ____ months to seventeen years.\Question: Choose the right answer from options given a) one b) six c) nine d) three

Ex Output:
c


Ex Input:
Earthworms have ____ pairs of hearts.\Question: Choose the right answer from options given a) seven b) five c) one d) no

Ex Output:
b


Ex Input:
Cows are pregnant for ____ months and are given a rest period from milking between calvings.\Question: Choose the right answer from options given a) six b) eight c) two d) nine

Ex Output:

d