The Observed Characteristics of a Quasar Are a

The observed characteristics of a quasar are a

A) diffuse circular image, no redshift of the spectrum, and often a very bright radio source.
B) starlike image, with a highly variable Doppler spectrum that shifts from red to blue, and often a very bright radio source.
C) starlike image, a highly redshifted spectrum, and sometimes an intense radio emitter.
D) starlike image, an extremely blueshifted spectrum, and often an intense radio emitter.