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:
Water weighs about ____ pounds per gallon.\Question: Choose the right answer from options given a) seven b) ten c) zero d) nine

Ex Output:
b


Ex Input:
Laparoscopic surgery is performed via three or ____ small incisions in the abdomen.\Question: Choose the right answer from options given a) nine b) six c) five d) four

Ex Output:
d


Ex Input:
Healthcare providers diagnose ____ general types of insomnia.\Question: Choose the right answer from options given a) two b) eight c) one d) three

Ex Output:

a