The correct answer is (C) Coordinated waves of exactly the same wavelength.
Laser light is considered coherent because it is composed of waves that have a consistent phase relationship and exactly the same wavelength. In a laser, the light waves are produced through a process called stimulated emission, where atoms or molecules are stimulated to emit light with specific properties. This process results in the production of photons that have the same frequency and phase, leading to a highly organized and synchronized beam of light.
In contrast, incoherent light sources such as ordinary light bulbs or the Sun emit light waves with various wavelengths and phases, resulting in a mix of uncoordinated waves. Divergent beams, as mentioned in option (D), refer to the spreading out of a beam of light as it propagates, which is a characteristic of many light sources but not specific to coherence.