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:
Decompression illness is a continuum from ____ symptoms or signs to severe multisystem involvement.\Question: Choose the right answer from options given a) nine b) three c) no d) one

Ex Output:
c


Ex Input:
Digital bandwidth enables signal to be condensed as a five to ____ ratio.\Question: Choose the right answer from options given a) one b) nine c) seven d) six

Ex Output:
a


Ex Input:
Organic chemists are also very interested in the ____ dimensional shapes of molecules.\Question: Choose the right answer from options given a) six b) three c) no d) ten

Ex Output:

b