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:
Quadrupeds are animals with ____ feet, such as cows.\Question: Choose the right answer from options given a) four b) six c) ten d) two

Ex Output:
a


Ex Input:
All quetzals have ____ legs.\Question: Choose the right answer from options given a) four b) zero c) eight d) ten

Ex Output:
a


Ex Input:
Large nests provide a home for up to ____ million insects.\Question: Choose the right answer from options given a) one b) four c) five d) zero

Ex Output:

c