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: producing thrust causes something to move, Fact2: Opposite forces cause the thrust of the rocket., Question: Opposite what cause something to move? (A) forces (B) voltage (C) seats (D) brakes (E) friction (F) stationary (G) nerves (H) arteries
Output:
A