TASK DEFINITION: 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").
PROBLEM: 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

SOLUTION: C

PROBLEM: Jeff noticed that the big dipper was in a different spot in the sky at 2am than where it was at 10pm. Why? (A) because of the earth's orbit (B) the stars had rotated (C) Jeff had been instantly transported thousands of miles from where he'd been at 10pm. (D) the earth had turned

SOLUTION: D

PROBLEM: Why animal may use a rock as shelter (A) Centipede (B) Dolphin (C) Seagull (D) Dog

SOLUTION:
A