If a wave transfers from one medium to another medium with different properties, which statement is true?(1 point)

Which of the following is the best option?

a) The period and the speed of the wave change proportionally.

b) The frequency remains constant.

c) The period changes, while the wavelength and the speed of the wave remain the same.

d) The frequency changes, while the wavelength and the speed of the wave remain the same.

d) The frequency changes, while the wavelength and the speed of the wave remain the same.