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:
Whales are divided into ____ categories, based on their teeth.\Question: Choose the right answer from options given a) two b) four c) nine d) ten

Ex Output:
a


Ex Input:
Scorpions also have ____ legs.\Question: Choose the right answer from options given a) eight b) zero c) nine d) ten

Ex Output:
a


Ex Input:
Guns kill a child every ____ hours.\Question: Choose the right answer from options given a) seven b) nine c) five d) two

Ex Output:

d