The right answer is visible light.
Visible light, also called visible spectrum or optical spectrum is the part of the electromagnetic spectrum that is visible to the human eye.
There is no exact limit to the visible spectrum: the human eye adapted to light generally has a maximum sensitivity to wavelength light of about 550 nm, which corresponds to a yellow-green color. Generally, the response of the eye is considered to cover wavelengths of 380 nm to 780 nm although a range of 400 nm to 700 nm is more common. These extremes correspond to the violet and red colors respectively. However, the eye may have some visual response in even wider wavelength ranges.
