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:
Photosynthesis occurs in ____ phases.\Question: Choose the right answer from options given a) four b) two c) nine d) five

Ex Output:
b


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:
Bullfrogs can live up to ____ years .\Question: Choose the right answer from options given a) four b) three c) one d) seven

Ex Output:

a