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:
All cattle have a ____ chambered stomach, consisting of a rumen, reticulum, omasum and abomasum.\Question: Choose the right answer from options given a) ten b) four c) six d) two

Ex Output:
b


Ex Input:
Many tortoises can retract their head, their ____ limbs and tail into the shell for protection.\Question: Choose the right answer from options given a) no b) one c) two d) four

Ex Output:
d


Ex Input:
Adult tarantulas require a minimum of ____ to five crickets a week.\Question: Choose the right answer from options given a) seven b) three c) four d) five

Ex Output:

b