Answer: C. solar energy
Explanation: Photosynthesis is a phenomenon in which green plants containing chlorophyll use sunlight as a source of energy to convert carbon dioxide and water to form glucose and oxygen.
Photosynthesis is the process used by plants, algae and certain bacteria to convert energy from sunlight and turn it into chemical energy in the form of glucose which is used as a source of energy by many organisms. Glucose contains energy in the form of chemical energy stored in the bonds.
\(6CO_2+6H_2O\overset{sunlight}\rightarrow C_6H_{12}O_6+6O_2\)
