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:
Dunes are of ____ types - linear and parabolic.\Question: Choose the right answer from options given a) three b) four c) ten d) two

Ex Output:
d


Ex Input:
Heat pumps give off ____ fumes or harmful products of combustion.\Question: Choose the right answer from options given a) four b) zero c) six d) no

Ex Output:
d


Ex Input:
Asthma accounts for ____ in six of all pediatric emergency visits in the United States.\Question: Choose the right answer from options given a) four b) seven c) one d) six

Ex Output:

c