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:
Young emus are very vulnerable to disease until they are about ____ months old.\Question: Choose the right answer from options given a) no b) ten c) six d) three

Ex Output:
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:
Firebrat eggs hatch in about ____ weeks.\Question: Choose the right answer from options given a) ten b) one c) two d) no

Ex Output:

c