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").

the Grand Canyon was formed by the Colorado River doing what over long periods of time? (A) blazing (B) melting (C) moving steadily (D) evaporating
C
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").

the Grand Canyon was formed by the Colorado River doing what over long periods of time? (A) blazing (B) melting (C) moving steadily (D) evaporating
user
C
assistant
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").

the Grand Canyon was formed by the Colorado River doing what over long periods of time? (A) blazing (B) melting (C) moving steadily (D) evaporating
C