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:
Most school aged children pass at least ____ stools per week, with an average of one stool per day.\Question: Choose the right answer from options given a) three b) one c) six d) zero

Ex Output:
a


Ex Input:
Ruminants have an even number of toes on each foot and a stomach with either three or ____ chambers.\Question: Choose the right answer from options given a) four b) two c) seven d) five

Ex Output:
a


Ex Input:
Octopuses have ____ reproductive strategies.\Question: Choose the right answer from options given a) zero b) two c) seven d) six

Ex Output:

b