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:
Pupae usually transform into adults ____ to three days later.\Question: Choose the right answer from options given a) one b) two c) no d) eight

Ex Output:
b


Ex Input:
Amelia Island is the only territory in American history to serve under ____ flags.\Question: Choose the right answer from options given a) eight b) no c) six d) five

Ex Output:
a


Ex Input:
Every drug has ____ names, a chemical name, a brand name, and an official name.\Question: Choose the right answer from options given a) three b) six c) ten d) five

Ex Output:

a