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:
Hydra has ____ distinct methods of reproduction, asexual and sexual.\Question: Choose the right answer from options given a) two b) zero c) no d) ten

Ex Output:
a


Ex Input:
Insects have ____ pairs of legs and three body segments.\Question: Choose the right answer from options given a) one b) nine c) no d) three

Ex Output:
d


Ex Input:
Stairs account for three times more injuries to children under age ____ than do toys.\Question: Choose the right answer from options given a) six b) five c) no d) one

Ex Output:

b