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:
Spores have ____ combinations of sexes.\Question: Choose the right answer from options given a) four b) five c) seven d) three

Ex Output:
a


Ex Input:
Vision problems affect one in ____ school-aged children.\Question: Choose the right answer from options given a) six b) four c) seven d) one

Ex Output:
b


Ex Input:
Shigellosis usually resolves in ____ to seven days but can last for weeks.\Question: Choose the right answer from options given a) six b) eight c) five d) ten

Ex Output:

c