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:
Hamsters can live to be three to ____ years old.\Question: Choose the right answer from options given a) four b) two c) three d) nine

Ex Output:
a


Ex Input:
Most roots require from three to ____ weeks to dry sufficiently to be safe.\Question: Choose the right answer from options given a) seven b) five c) three d) six

Ex Output:

d