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]: Mechanical stability comes from having fused quartz, in ____ gravity, cold.\Question: Choose the right answer from options given a) five b) zero c) six d) two
[EX A]: b

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

[EX Q]: Cockroaches have ____ stages of development - egg, nymph, and adult.\Question: Choose the right answer from options given a) four b) ten c) one d) three
[EX A]:
d