Answer:
There are several modalities, or methods, of treatment: individual therapy, group therapy, couples therapy, and family therapy
Explanation:
This room is called Substation
For a standing wave on a string, the wavelength is equal to twice the length of the string:

In our problem, L=50.0 cm=0.50 m, therefore the wavelength of the wave is

And the speed of the wave is given by the product between the frequency and the wavelength of the wave:
The correct answer should be bounced off since the light ray hit the surface and reflected towards a new location. It therefore bounced off.