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:
Paleontologists specialize in ____ main areas.\Question: Choose the right answer from options given a) eight b) five c) no d) six

Ex Output:
b


Ex Input:
Women gain ____ years per child they had.\Question: Choose the right answer from options given a) ten b) nine c) four d) two

Ex Output:
d


Ex Input:
Blood is made up of ____ parts.\Question: Choose the right answer from options given a) no b) eight c) five d) four

Ex Output:

d