A CD Player and Its Battery Together Do 500 KJ

A CD player and its battery together do 500 kJ of work.The battery also releases 250 kJ of energy as heat and the CD player releases 50 kJ as heat due to friction from spinning.What is the change in internal energy of the system,with the system regarded as the battery and CD player together?

A) +200 kJ
B) (-700 kJ)
C) (-800 kJ)
D) (-200 kJ)
E) (-750 kJ)