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]: Human feet bear average five to ____ hundreds tons of weight everyday.\Question: Choose the right answer from options given a) six b) eight c) five d) nine
[A]: a


[Q]: Many people have ____ symptoms until they suffer chest pains or a heart attack.\Question: Choose the right answer from options given a) three b) one c) no d) seven
[A]: c


[Q]: Modulation is the first of ____ efficiency related features unique to the linear compressor.\Question: Choose the right answer from options given a) three b) nine c) five d) seven
[A]:
a