Conservation of Energy with Newton's Laws and Kinematics

Two boxes (Mass A and Mass B) are connected to each other by a pulley, as shown in the figure to the left.

The system is released from rest, and the 1.00-kg box falls through a distance of 1.00 m to the floor. The surface of the table is frictionless.

What is the Kinetic Energy of Box B just before it reaches the floor?