Which one among the following statements is correct?

The Principle of Conservation of Mechanical Energy states that the total mechanical energy (the sum of kinetic energy and potential energy) of a system remains constant (is conserved) if only conservative forces do work on it. Conservative forces, such as gravity or electrostatic forces, are path-independent.

• Option B is incorrect because non-conservative forces (like friction or air resistance) dissipate mechanical energy into other forms, such as heat or sound.
• Option C is incorrect because it is an incomplete statement; mechanical energy is only constant under the specific condition mentioned in Option A.
• Option D is incorrect because potential energy is only defined for conservative forces. Non-conservative forces do not have an associated potential energy function because the work done by them depends on the path taken.