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:
Tetrapods are animals that have ____ legs or leg-like appendages.\Question: Choose the right answer from options given a) four b) one c) ten d) six

Ex Output:
a


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:
Eggs are only of value when ____ maggots or later insect stages are present.\Question: Choose the right answer from options given a) no b) four c) six d) two

Ex Output:

a