In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").

[Q]: the presence of which of these is required for the formation of cavernous chambers? (A) some carbonated soda (B) some carbon dioxide (C) some carbonic acid (D) carbon monoxide gas
[A]: C


[Q]: Rocket engines can lift rockets because (A) of how much fuel they use (B) of how fast they are (C) of the power the hit the ground with (D) of how tall they are
[A]: C


[Q]: what do animals need to protect them from bad weather? (A) housing (B) food (C) water (D) clothing
[A]:
A