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:
Indian reservations are part of five of the nation's ____ poorest counties.\Question: Choose the right answer from options given a) seven b) nine c) ten d) two

Ex Output:
c


Ex Input:
Atrial fibrillation increases a person's stroke risk by ____ times.\Question: Choose the right answer from options given a) six b) two c) three d) zero

Ex Output:

a