Detailed Instructions: In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").
Problem:Fact1: most canyons are formed by flowing rivers through erosion over long periods of time, Fact2: Geological erosion is natural occurring erosion over long periods of time., Question: Most canyons are formed by rivers flowing and what type of erosion? (A) forces (B) mechanical (C) uncontrolled (D) geological (E) Water expanding (F) flooding (G) thrust (H) barrel-shaped
Solution:
D