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:
Big bluestem grows up to ____ feet tall.\Question: Choose the right answer from options given a) seven b) no c) nine d) eight

Ex Output:
c


Ex Input:
Some motors contain ____ gears and spin very fast, and have little if any torque.\Question: Choose the right answer from options given a) four b) three c) five d) no

Ex Output:
d


Ex Input:
Females generally give birth to only ____ or four surviving young during their reproductive life.\Question: Choose the right answer from options given a) one b) four c) three d) five

Ex Output:

c