total energy at any point is the sum of kinetic energy and potential energy. here the charge is in electric field region, hence it has electric potential energy.
As the charge moves from one point A to another point, the sum of electric potential energy and kinetic energy always remains same. This is as per conservation of energy principle.
hence the correct choice is
A. The sum of the potential energy and the kinetic energy at A is the same as that at B.
