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').

[Q]: Tilt consists of ____ small surface vents.\Question: Choose the right answer from options given a) zero b) three c) seven d) no
[A]: b


[Q]: Aridity presents ____ main obstacles to solitary behavior.\Question: Choose the right answer from options given a) no b) three c) two d) five
[A]: c


[Q]: Dragons are usually ____ legged, around the size of a small home to that of a chapel.\Question: Choose the right answer from options given a) three b) eight c) six d) four
[A]:
d