In an ecosystem, the 10% of energy is transferred from one trophic level to the next in the form of
Correct option is C. chemical energy
The first trophic level in any food chain is of producers which are green plants. They capture sunlight and convert solar energy into chemical energy. This energy is then transferred to other organisms as they feed on producers. The energy transferred from one trophic level follows 10 per cent law according to which only 10% of the energy is transferred from one trophic level to subsequent higher trophic level. Thus this energy is in the form of chemical energy.
So, the correct answer is 'chemical energy'.