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").

Why would a lightbulb be dark? (A) the bulb needs to be charged (B) the room is too bright (C) the circuit is incomplete (D) it ran out of electricity
C

Which of these objects could combust (A) Seashells (B) Grass (C) A cat (D) A paint can
D

Which promotes the creation of serotonin? (A) Jupiter (B) Venus (C) the Sun (D) the Moon

C