Question

which best explains why one laser beam might appear blue and another laser beam might appear red?
the energy in laser beams is concentrated.
the energy in laser beams is scattered.
each laser beam is made up of all visible wavelengths of light.
each laser beam is made up of one specific wavelength of light.

Explanation:

The color of light is determined by its wavelength. Different - colored laser beams have different wavelengths. Lasers emit light of a single, specific wavelength. This is why one laser beam can appear blue and another red.

Answer:

Each laser beam is made up of one specific wavelength of light.