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]: Insects have ____ common types of metamorphosis.\Question: Choose the right answer from options given a) six b) eight c) two d) seven
[A]: c


[Q]: Meteorologists rely mainly on ____ types of satellites.\Question: Choose the right answer from options given a) four b) two c) ten d) three
[A]: b


[Q]: Parallel transfer is the simultaneous transmission of the ____ bit-voltages that constitute a byte.\Question: Choose the right answer from options given a) five b) zero c) eight d) ten
[A]:
c