Kindly Study the following questions carefully and

Solution

Autotroph means self-feeding in Greek or producer and is an organism that produces complex organic compounds such as carbohydrates, fats, and proteins from simple substances using energy from light. They are the producers in a food chain, such as plants on land or algae in water. Ex: Plants are the most familiar type of autotroph. Algae, which live in water and whose larger forms are known as seaweed, is autotrophic. Phytoplankton, tiny organisms that live in the ocean, are autotrophs. Some types of bacteria are autotrophs. A heterotroph is an organism that absorbs organic carbon rather than fix carbon from inorganic sources such as carbon dioxide in order to be able to produce energy and synthesize compounds to maintain its life. An organotroph is an organism that obtains hydrogen or electrons from organic substrates. Hence, option A is correct.