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:
Some male fish return after just ____ years.\Question: Choose the right answer from options given a) no b) two c) one d) six

Ex Output:
b


Ex Input:
Food chains consist of ____ trophic levels.\Question: Choose the right answer from options given a) ten b) three c) one d) four

Ex Output:
d


Ex Input:
Islamic spirituality is active in all ____ aspects of human experience.\Question: Choose the right answer from options given a) nine b) four c) two d) ten

Ex Output:

b