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:
Mothers usually give birth to one, two, or ____ babies at a time.\Question: Choose the right answer from options given a) three b) zero c) five d) ten

Ex Output:
a


Ex Input:
Sugar beet is strongly self-sterile setting few or ____ seeds under strict isolation.\Question: Choose the right answer from options given a) three b) no c) five d) nine

Ex Output:
b


Ex Input:
Most aquatic life does well in water with oxygen concentrations of ____ parts per million.\Question: Choose the right answer from options given a) four b) nine c) five d) six

Ex Output:

b