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:
Spores have ____ combinations of sexes.\Question: Choose the right answer from options given a) four b) five c) seven d) three

Ex Output:
a


Ex Input:
Government buildings fly flags of the ____ nations.\Question: Choose the right answer from options given a) ten b) no c) seven d) two

Ex Output:
d


Ex Input:
Connection is a ____ way exchange of attention.\Question: Choose the right answer from options given a) four b) ten c) two d) six

Ex Output:

c