You will be given a definition of a task first, then some input of the task.
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").

Fact1: high mountains with well-rounded peaks can be formed by collision of crustal plates, Fact2: Plate Tectonics is the study of crustal plates and their boundaries., Question: high mountains with well-rounded peaks can be formed by collision of what? (A) plate tectonics (B) unicellular organisms (C) islets of Langerhans (D) changes in size (E) deposits (F) permeable walls (G) trucks and cars (H) rapid changes occur
Output:
A