The Typical Optical Spectrum of a Quasar Shows

The typical optical spectrum of a quasar shows:

A) very redshifted emission lines superimposed upon a weak continuum of radiation.
B) a series of very blueshifted emission lines, with no continuum component.
C) a continuum of radiation crossed by a sequence of very redshifted absorption lines.
D) a sequence of highly blueshifted absorption lines upon a continuum of radiation.