Which statement is true about the law of conservation of energy for an object released from a certain height above the ground? a. in the absence of any external forces and at any point, the kinetic energy and the potential energy are always equal. b. in the absence of any external forces and at any point, the kinetic energy is always greater than the potential energy. c. in the absence of external forces and at any point, the potential energy is always greater than the kinetic energy. d. in the absence of external forces and at any point, the sum of the kinetic energy and the potential energy is always constant.