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]: Real airplanes have round engines and ____ wings.\Question: Choose the right answer from options given a) four b) six c) three d) two
[A]: d


[Q]: Human malaria is caused by ____ species of Plasmodium . .\Question: Choose the right answer from options given a) six b) ten c) seven d) four
[A]: d


[Q]: Seizures occur in ____ stages.\Question: Choose the right answer from options given a) two b) six c) four d) nine
[A]:
c