Only 20% to 30% of the Energy Stored in the Chemical

Only 20% to 30% of the energy stored in the chemical bonds of gasoline molecules is transformed into mechanical energy; the other 70% to 80% is dissipated as waste heat.Which statement explains this phenomenon?

A) The first law of thermodynamics.
B) The second law of thermodynamics.
C) When energy is converted from one form to another, some of the energy is converted into heat.
D) Both the first and second laws of thermodynamics.
E) Both the second law of thermodynamics, as well as the observation that the conversion of energy involves some energy being converted to heat.