Carbon and energy requirements of autotrophic organisms are fulfilled by:

The correct answer is option 1 i.e. Photosynthesis.AutotrophAutotrophic organisms are that prepare their own food.The chloroplast helps in preparing food.They obtain ENERGY from inorganic sources by CONVERTING light energy into CHEMICAL energy.Carbon and energy requirements of autotrophic organisms are fulfilled by photosynthesis.It is a process in which autotrophic organisms utilize carbon dioxide and water in the presence of sunlight and chlorophyll to FORM carbohydrates, the energy source.They are placed at the primary level in the food chain.Green plants, algae and a few photosynthetic BACTERIA are examples of autotrophs.