Which one of the following radiations is non-ionising?

Answer: Option D

Ultraviolet light radiation is non-ionizing.
Non-ionizing radiation includes visible, infrared, and ultraviolet light; microwaves; radio waves; and radiofrequency energy from cell phones.
Ultraviolet (UV) radiation is a form of non-ionizing radiation that is emitted by the sun and artificial sources, such as tanning beds.