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:
Vision disorders affect ____ in every four school-age children.\Question: Choose the right answer from options given a) nine b) one c) five d) six

Ex Output:
b


Ex Input:
Pairs encodes all sets of objects with ____ components.\Question: Choose the right answer from options given a) ten b) five c) two d) no

Ex Output:
c


Ex Input:
Most foods are actually a combination of all ____ macronutrients.\Question: Choose the right answer from options given a) nine b) ten c) two d) three

Ex Output:

d