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:
Facial features are smooth and very ____ dimensional.\Question: Choose the right answer from options given a) zero b) four c) ten d) three

Ex Output:
d


Ex Input:
Birds have ____ eyes.\Question: Choose the right answer from options given a) eight b) five c) nine d) two

Ex Output:
d


Ex Input:
Autism is ____ to four times more common in boys than girls.\Question: Choose the right answer from options given a) no b) four c) three d) five

Ex Output:

c