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]: Astronomers fall in ____ classes - professionals and amateurs.\Question: Choose the right answer from options given a) two b) four c) six d) zero
[EX A]: a

[EX Q]: Traditional neon electrifies the inert gas from ____ directions.\Question: Choose the right answer from options given a) two b) nine c) one d) six
[EX A]: a

[EX Q]: Brazil is among the top ____ producers of sugar cane.\Question: Choose the right answer from options given a) three b) five c) two d) zero
[EX A]:
a