An Athlete Doing Push-Ups Performs 650 KJ of Work and Loses

An athlete doing push-ups performs 650 kJ of work and loses 425 kJ of thermal energy through heating.What is the change in the internal (thermal) energy of the athlete?

A) -225 kJ
B) -1075 kJ
C) 1075 kJ
D) 225 kJ
E) 276 kJ