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:
Vision disorders affect one in every ____ school-age children.\Question: Choose the right answer from options given a) five b) four c) nine d) one

Ex Output:
b


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:
Nymphs emerge within ____ to seven days.\Question: Choose the right answer from options given a) eight b) no c) five d) three

Ex Output:

c