Two Masses Are Connected by a String Which Passes Over

Multiple Choice

Two masses are connected by a string which passes over a pulley with negligible mass and friction. One mass hangs vertically and one mass slides on a frictionless horizontal surface. The vertically hanging mass is 6.00 kg and the mass on the horizontal surface is 4.00 kg. The acceleration of the 4.00 kg mass is

A) 1.98 m/s² to the left.
B) 3.92 m/s² to the left.
C) 5.88 m/s² to the left.
D) 6.75 m/s² to the left.
E) 7.84 m/s² to the left.