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:
Infants usually die of pneumonia or other infections before reaching ____ years of age.\Question: Choose the right answer from options given a) nine b) four c) zero d) eight

Ex Output:
b


Ex Input:
Hummingbirds feed every ____ to fifteen minutes from sun-up to sundown.\Question: Choose the right answer from options given a) nine b) seven c) four d) ten

Ex Output:
d


Ex Input:
Children typically drown in under ____ minutes.\Question: Choose the right answer from options given a) one b) seven c) three d) no

Ex Output:

c