Unlike the Ultraviolet Photons Originally Emitted by the Embedded Stars

Multiple Choice

Unlike the ultraviolet photons originally emitted by the embedded stars of an emissionnebula, the photons emitted by the recombination of electrons with atoms:

A) do not escape the nebula.
B) escape the nebula.
C) are re-absorbed by neutral hydrogen atoms.
D) bounce around inside the nebula.
E) are scattered by the dust particles.