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:
National immunization vaccinates all children under ____ against polio.\Question: Choose the right answer from options given a) zero b) four c) ten d) five

Ex Output:
b

Ex Input:
Parapsychologists have ____ basic approaches to their subject matter.\Question: Choose the right answer from options given a) three b) two c) ten d) five

Ex Output:
b

Ex Input:
Most cod are between six and twelve pounds as adults, and weigh between four and ____ pounds.\Question: Choose the right answer from options given a) two b) seven c) five d) ten

Ex Output:
d