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').

Sound waves travel through the air in a similar manner, but in all ____ dimensions.\Question: Choose the right answer from options given a) three b) five c) nine d) one
a

Redwoods reproduce ____ ways.\Question: Choose the right answer from options given a) zero b) two c) six d) nine
b

All mass spectrometers consist of ____ distinct regions.\Question: Choose the right answer from options given a) three b) one c) two d) zero

a