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:
Cows can be up to ____ times more active than normal while in heat.\Question: Choose the right answer from options given a) eight b) nine c) two d) six

Ex Output:
a


Ex Input:
Streptomyces are of special interest for ____ reasons.\Question: Choose the right answer from options given a) nine b) seven c) four d) two

Ex Output:
d


Ex Input:
Sugar gliders have ____ front teeth.\Question: Choose the right answer from options given a) no b) two c) nine d) six

Ex Output:

b