Mechanical Energy of a system: Conceptual Problem

[Yosty22]

Homework Statement

Which of the following statements is/are true?
Choose all that apply.

a. The total mechanical energy of a system, at anyone instant, is either all kinetic or all potential energy.
b. The total mechanical energy of a system is equally divided between kinetic and potential energy.
c. The total mechanical energy of a system is constant only if conservative forces act.
d. The total mechanical energy of a system is constant only if nonconservative forces act.
e. Mechanical energy can be dissipated to nonmechanical forms of energy.

Homework Equations

N/A

The Attempt at a Solution

I believe the answers are both c and e. I just wanted to clear up letter c because conservative forces are the ones that make total mechanical energy of a system constant, correct? Not nonconservative forces, because they would dissipate over time. Is this correct?

 

[haruspex]

Your answers look right to me.