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:
Argentine ants are able to establish new colonies with as little as ____ worker ants and one queen.\Question: Choose the right answer from options given a) no b) two c) ten d) five

Ex Output:
c


Ex Input:
Avian kidneys have ____ kinds of nephrons.\Question: Choose the right answer from options given a) four b) eight c) no d) two

Ex Output:
d


Ex Input:
Fleeces weigh five to ____ pounds and have a staple length of six to twelve inches.\Question: Choose the right answer from options given a) ten b) zero c) eight d) nine

Ex Output:

a