A String of Mass M Is Under Tension,and the Speed $\sqrt { 2 }$

A string of mass m is under tension,and the speed of a wave in the string is v.What will be the speed of a wave in the string if the mass of the string is increased to 2m but with no change in the length or tension?

A) v/2
B) v/ $\sqrt { 2 }$
C) v $\sqrt { 2 }$
D) 2v
E) 4v