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:
Cows have four stomachs, and the first ____ yield merchantable tripe.\Question: Choose the right answer from options given a) two b) five c) zero d) three

Ex Output:
d


Ex Input:
Vampires generally are male, and rabies is ____ times more frequent in men than in women.\Question: Choose the right answer from options given a) no b) two c) zero d) seven

Ex Output:
d


Ex Input:
Most scientists consider swamp s, marsh es, and bog s to be the ____ major kinds of wetlands.\Question: Choose the right answer from options given a) six b) five c) three d) seven

Ex Output:

c