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 Q]: Many scientists believe the neutrino has ____ mass at all.\Question: Choose the right answer from options given a) eight b) zero c) two d) no
[EX A]: d

[EX Q]: National forests have regulations that restrict ____ wheeler use to established roads.\Question: Choose the right answer from options given a) no b) four c) six d) nine
[EX A]: b

[EX Q]: Asthma medications come in ____ different forms.\Question: Choose the right answer from options given a) six b) two c) nine d) three
[EX A]:
d