I have a Physics question!?

C. The velocity remains the same. The Speed of the wave on the string is determined by the the tension in the string and the mass divided by the length of the string. This makes sense intuitively because a wave is merely a disturbance on the molecular level. This disturbance is more easily propagated if the molecules are pulled very tightly together or in other words, the tension is high. It also makes sense that if their are more molecules or, a greater mass per unit length, the string has more inertia which will make it take longer to propagate. The formula I cited earlier is written as V=sqrt(FT/(m/l). Where V=velocity, sqrt=square root, FT=force of tension in the string, m=mass of string, and l= length of sting. So, my point is that unless you change the tension, the mass, or the length of the string, the velocity remains constant which would make the answer C.