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:
Teething begins for most babies around ____ to six months.\Question: Choose the right answer from options given a) three b) four c) five d) seven

Ex Output:
b


Ex Input:
Statistics show that within ____ years of divorce, many people marry a second time.\Question: Choose the right answer from options given a) four b) nine c) six d) three

Ex Output:
d


Ex Input:
Skin is composed of ____ layers.\Question: Choose the right answer from options given a) three b) seven c) nine d) four

Ex Output:

a