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").
Q: Fact1: fossils are formed when layers of sediment cover the remains of organisms over time, Fact2: Natural gas is a fossil fuel., Question: What is formed from layers of sediment covering the remains of organisms over time? (A) metal (B) cold (C) rings (D) coral reef (E) sea urchins (F) natural gas (G) exoskeleton (H) shells
A:
F