The correct options are
C The energy stored in an object due to its position is called potential energy.
D The energy possessed by an object by virtue of its motion is called kinetic energy.
The energy stored in an object due to its position is called potential energy. Potential energy is defined with respect to a reference point.
The energy possessed by an object by virtue of its motion is called kinetic energy.
The sum of kinetic and potential energy is called mechanical energy.