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:
Wolverines reproduce every ____ or three years.\Question: Choose the right answer from options given a) two b) three c) one d) four

Ex Output:
a


Ex Input:
All mass spectrometers consist of ____ distinct regions.\Question: Choose the right answer from options given a) three b) one c) two d) zero

Ex Output:
a


Ex Input:
Termites have ____ body parts, the head, thorax and adbomen.\Question: Choose the right answer from options given a) three b) zero c) six d) eight

Ex Output:

a