Question

the electromagnetic spectrum: denotes the wavelengths people see as light. is just a portion of the wavelengths people see as light. refers to the wavelengths that human vision cannot detect. contains the wavelengths people see as light.

Explanation:

The electromagnetic spectrum encompasses a wide range of wavelengths. Visible light, which humans can see, is only a part of it. So the electromagnetic spectrum contains the wavelengths people see as light.

Answer:

denotes the wavelengths people see as light. - Incorrect
is just a portion of the wavelengths people see as light. - Incorrect
refers to the wavelengths that human vision cannot detect. - Incorrect
contains the wavelengths people see as light. - Correct