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:
Marriage is the legal union of ____ people.\Question: Choose the right answer from options given a) one b) no c) five d) two

Ex Output:
d


Ex Input:
Routers are basically systems, which connect ____ networks together.\Question: Choose the right answer from options given a) three b) two c) nine d) six

Ex Output:
b


Ex Input:
Light affects plants in ____ ways.\Question: Choose the right answer from options given a) four b) seven c) ten d) two

Ex Output:

d