A 900 Kg Person Is Sitting in a 100 Kg Boat

Multiple Choice

A 90.0 kg person is sitting in a 100 kg boat, which is floating at rest on a lake. In the boat is a stone with a mass of 5.00 kg. The person throws the stone at 4.00 m/s horizontally in the NORTH direction. The kinetic energy of the boat and person after throwing the stone is

A) 5.20 J.
B) 40.0 J.
C) 1.05 J.
D) 2.75 J.