Answe.................................................................................................................................................................................................
Answer:
In the electromagnetic spectrum, the visible spectrum is the part, which is perceptible to the human eye. The electromagnetic spectrum in this array of wavelengths is known as simply light or the visible light. A general human eye will react towards the wavelengths in the range between 380 to 740 nm. A human eye sees the sky as blue that comes in the wavelength 490 nm because of the scattering of the visible light by the particles in the atmosphere. This concludes that 490 nm is the sole wavelength, which is reaching the eye.
A. when evaluating a source for reliability, if they are talking about a product from a company that sponsors them they may not be honest, or if they are sponsored by a reliable company they can be trusted it depends what way you look at it.