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:
Children are more likely than adults to show ____ symptoms even if they are infected.\Question: Choose the right answer from options given a) eight b) two c) no d) six

Ex Output:
c


Ex Input:
Smoking is responsible for one out of ____ American deaths.\Question: Choose the right answer from options given a) five b) six c) nine d) seven

Ex Output:
a


Ex Input:
Most museums keep between one and ten percent of their collections on display at any ____ time.\Question: Choose the right answer from options given a) no b) seven c) zero d) one

Ex Output:

d