Explanation

Detritivores are heterotrophic decomposers that ingest and digest non-living organic particulate matter (detritus, decaying plant material, leaf litter, and carrion), accelerating natural nutrient recycling:

– 1. Earthworms (Correct): Classic soil detritivores that consume decaying fallen leaves, plant roots, and soil organic debris, excreting nutrient-rich vermicast.
– 3. Millipedes (Correct): Myriapods that live beneath leaf litter and fallen logs, feeding almost exclusively on decomposing vegetation and rotting plant tissues.
– 5. Woodlice (Correct): Terrestrial isopods that scavenge and feed on rotting wood, decaying leaves, and decomposing vegetal waste.
– 2. Jellyfish (Incorrect): Pelagic aquatic carnivores that capture living zooplankton, small fish, and crustaceans using stinging nematocysts.
– 4. Seahorses (Incorrect): Small marine teleost fish that are active ambush predators, feeding on live copepods, mysids, and tiny invertebrates.

Hence, organisms 1, 3, and 5 are detritivores — Option C.