Two Masses, 5 Kg and 3 Kg, Are Connected by Massless

Multiple Choice

Two masses, 5 kg and 3 kg, are connected by massless string. A cord is then attached to the 5-kg mass and the two masses are pulled across a smooth flat table. If the masses are moving at constant speed, what is the tension in the massless string (between the two masses) ?

A) 0 N
B) 50 N
C) 20 N
D) 30 N