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:
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:
Humans normally produce only ____ sets of teeth.\Question: Choose the right answer from options given a) nine b) eight c) two d) three

Ex Output:
c


Ex Input:
Giant pandas move on all ____ legs.\Question: Choose the right answer from options given a) five b) four c) nine d) seven

Ex Output:

b