Given the task definition and input, reply with output. 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: Earthworms are important deposit feeders that help form and enrich soil., Fact2: Earthworms are perhaps the most familiar decomposer., Question: What can help form and enrich soil? (A) Most plants (B) whales (C) the Sun (D) decomposers (E) swamp vegetation (F) shrub beds (G) phytoplankton (H) fossil fuels
D