Which organisms fix the Sun's radiant energy to make food from simple inorganic materials?

Producers

The correct answer is Option (1) →  Producers.

Producers are organisms like green plants, algae, and cyanobacteria that use photosynthesis to convert the Sun’s radiant energy into chemical energy (glucose). They use simple inorganic materials like carbon dioxide (CO₂) and water (H₂O) to make organic food.

Consumers (option 2) obtain their energy by consuming other organisms, including producers.

Decomposers (option 3) break down organic matter into simpler substances and play a crucial role in nutrient recycling.

Primary carnivore(option 4)  refers to an organism that directly consumes herbivores or primary consumers as a source of food. In a food chain or food web, primary carnivores occupy a trophic level higher than herbivores but lower than secondary carnivores.