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: animals learn some behaviors from watching their (A) rocks (B) toys (C) caretakers (D) trees

SOLUTION: C

PROBLEM: The cell membrane keeps a cell from (A) replicating (B) getting lost (C) falling apart (D) running away

SOLUTION: C

PROBLEM: Which is the least massive? (A) the Earth (B) the moon (C) the sun (D) the solar system

SOLUTION:
B