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: sunlight and rain can cause a rainbow, Fact2: If sunlight is passed through a prism, a rainbow is produced., Question: what does a prism form? (A) Light (B) an image (C) water (D) rainbow (E) storm (F) mirror (G) a prism (H) Energy.
Output:
D