What is the main difference between mechanical and electromagnet waves?

Question

a)Mechanical waves involve transfer of energy; electromagnet waves do not.
b)Mechanical waves require a medium to travel in; electromagnet waves do not.
c)Mechanical waves have amplitude and wavelength; electromagnet waves do not.
d) Mechanical waves have speed and frequency; electromagnet waves do not.

is it C?

Answer 1

While an electromagnetic wave is called just a disturbance, a mechanical wave is considered a periodic disturbance. The answer is B

Answer 2

I think the answer may be B as well

Answer 3

I am from the future