Autotrophs are defined as organisms that:

• A. Must feed on other organisms
• B. Produce their own food
• C. Decompose dead matter
• D. Require oxygen

Answer: (B)

Autotrophs are organisms that produce their own organic molecules from inorganic carbon sources, using energy from either sunlight or chemical reactions. Through photosynthesis, plants, algae, and many bacteria convert CO2 and water into sugars, releasing oxygen. Some bacteria rely on chemosynthesis, obtaining energy from inorganic chemicals to drive carbon fixation. This self-sufficiency as primary producers distinguishes autotrophs from heterotrophs, which must obtain preformed organic matter by consuming other organisms. Chance differences like oxygen needs aren’t defining—some autotrophs can live without oxygen. So the essence is: autotrophs produce their own food from inorganic sources.