A Block of Mass,m,is Pushed Up Against a Spring,compressing It

Multiple Choice

A block of mass,m,is pushed up against a spring,compressing it a distance x,and is then released.The spring projects the block along a frictionless horizontal surface,giving the block a speed v.The same spring projects a second block of mass 4m,giving it a speed 3v.What distance was the spring compressed in the second case?

A) x
B) 2x
C) 3x
D) 4x
E) 6x