B) Dark light
C) Infrared light
D) Ultraviolet light
The correct option is D) Ultraviolet light.
Using ultraviolet light for the detection of fingerprints is one of the common methods used in criminal investigations.
When an object from which the fingerprint is to be taken is either sprayed or immersed in a fluorescent solution for 5 seconds to 2 minutes. Standard black lights are obtained from ardrox, basic yellow 40, and thenoyl europium chelate. Shine on the black light from the object can be seen when the ambient light in the area is lowered. It can be seen that the fingerprints glow between the fluorescent solution and the black light.