A Reflection Nebula Is Made Visible by

Multiple Choice

A reflection nebula is made visible by

A) thermal energy emitted as a continuous spectrum by very hot gas,much like that emitted by a hot body on Earth.
B) blue light,preferentially scattered by tiny dust grains.
C) emission lines from hydrogen,which itself has been ionized by UV light from embedded stars.
D) light from embedded stars,reflected over a wide range of wavelengths toward Earth by crystals of water.