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:
Ocular dryness responds to the use of artificial tears applied every ____ to three hours.\Question: Choose the right answer from options given a) no b) one c) three d) eight

Ex Output:
b


Ex Input:
Flatbed scanners can also record ____ dimensional objects of many sizes and shapes.\Question: Choose the right answer from options given a) eight b) one c) four d) three

Ex Output:
d


Ex Input:
Insects have three main body parts, ____ legs and antennae.\Question: Choose the right answer from options given a) five b) seven c) no d) six

Ex Output:

d