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').
--------
Question: Granite occurs in ____ separate masses.\Question: Choose the right answer from options given a) two b) eight c) nine d) no

Answer: a


Question: 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

Answer: b


Question: Electric cars run on electricity alone, so they are ____ emission vehicles.\Question: Choose the right answer from options given a) nine b) seven c) five d) zero

Answer:
d