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:
Chlorine is manufactured in ____ ways.\Question: Choose the right answer from options given a) four b) two c) nine d) seven

Ex Output:
b


Ex Input:
Most women notice their breasts become fuller and firmer within the first six to ____ weeks.\Question: Choose the right answer from options given a) four b) eight c) zero d) ten

Ex Output:
b


Ex Input:
Ozone is actually ____ oxygen atoms bonded together.\Question: Choose the right answer from options given a) ten b) one c) zero d) three

Ex Output:

d