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:
Some sources claim there are more like ____ million vertebrate animals in zoos.\Question: Choose the right answer from options given a) six b) five c) one d) three

Ex Output:
b


Ex Input:
Heme is made of ____ pyrrole groups united to form a porphyrin ring.\Question: Choose the right answer from options given a) five b) four c) eight d) six

Ex Output:
b


Ex Input:
Coyotes can easily leap an ____ foot fence or wall.\Question: Choose the right answer from options given a) ten b) no c) one d) eight

Ex Output:

d