Answer:
D. Electrical - electromagnetic and thermal​
Step-by-step explanation:
Energy is the capacity to do work, and it exists in various forms. Some of its forms are: nuclear energy, solar energy, electrical energy, mechanical energy, sound energy, light energy, heat/ thermal energy etc. These forms can be transformed from one to another. Example is the conversion of electrical energy into light energy and heat energy by an electrical Tungsten-bulb.
A space heater is an electrical device used for generation of majorly heat energy, thus it is powered by electrical energy. Therefore it transforms electrical energy into electromagnetic and thermal.