Answer: The correct answer is -
B) photosynthesis
Step-by-step explanation:
Photosynthesis can be described as process of creating food (in the form of glucose) in green plants, algae, and some protist (that are called producers). It uses inorganic molecules that are carbon dioxide and water in the presence of energy from sunlight to synthesise glucose and release oxygen as waste in surroundings.
It takes place in the specialized membrane bound organelles, called chloroplast.
Producers occupy the base of any food chain, which can be represented by energy pyramid, thus they produce enough chemical energy to support the entire ecosystem through photosynthesis.