Fact 1: Earthworms are important deposit feeders that help form and enrich soil. Fact 2: Earthworms are perhaps the most familiar decomposer. Given the two facts above, what can help form and enrich soil?

Choose your answer from:
(I) Most plants
(II) whales
(III) the Sun
(IV) decomposers
(V) swamp vegetation
(VI) shrub beds
(VII) phytoplankton
(VIII) fossil fuels
Answer:
(IV)