The correct answer is C. 3900 – 7600 angstrom.
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. It is made up of light with wavelengths between 390 and 760 nanometers. The visible spectrum is divided into seven colors: red, orange, yellow, green, blue, indigo, and violet. The colors of the visible spectrum are arranged in order of increasing wavelength, with red having the longest wavelength and violet having the shortest wavelength.
Option A is incorrect because it includes wavelengths that are too long to be visible to the human eye. Option B is incorrect because it includes wavelengths that are too short to be visible to the human eye. Option D is incorrect because it includes wavelengths that are both too long and too short to be visible to the human eye.