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:
Some infected people have ____ symptoms at all.\Question: Choose the right answer from options given a) four b) eight c) no d) five

Ex Output:
c


Ex Input:
Owls have ____ toes on each foot, like most birds.\Question: Choose the right answer from options given a) no b) seven c) four d) one

Ex Output:
c


Ex Input:
Most centrioles are made up of ____ sets of microtubule triplets, arranged in a cylinder.\Question: Choose the right answer from options given a) ten b) one c) nine d) zero

Ex Output:

c