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:
Malignant tumors are more dangerous, and survival times can range from ____ months to several years.\Question: Choose the right answer from options given a) one b) no c) ten d) six

Ex Output:
d


Ex Input:
Cattails contain ____ times the starch of an equal weight fo potatoes.\Question: Choose the right answer from options given a) six b) ten c) eight d) two

Ex Output:
b


Ex Input:
Irregular galaxies have ____ obvious spiral or elliptical structure.\Question: Choose the right answer from options given a) one b) two c) three d) no

Ex Output:

d