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:
Cyclic neutropenia tends to occur every three weeks and last ____ to six days at a time.\Question: Choose the right answer from options given a) six b) four c) five d) three

Ex Output:
d


Ex Input:
Mosquitoes have three body parts and ____ legs.\Question: Choose the right answer from options given a) two b) nine c) six d) eight

Ex Output:
c


Ex Input:
Insects also have ____ pair of legs coming from the thorax.\Question: Choose the right answer from options given a) five b) eight c) three d) nine

Ex Output:

c