A railroad car of mass 3.10×10^4 kg moving at 3.50 m/s collides and couples with two coupled railroad cars, each of the same mass as the single car and moving in the same direction at 1.20 m. What will be the resulting velocity of the three cars after the collision?

A) 3.50 m/s
B) 1.20 m/s
C) 2.35 m/s
D) Unable to determine without additional information