The Fact That Quasars Can Be Detected from Distances from Which

The fact that quasars can be detected from distances from which even the biggest and most luminous galaxies cannot be seen means that

A) they must be in directions where gravitational focusing by the masses of nearer galaxies makes them visible from Earth.
B) they must be far more luminous than the brightest galaxies.
C) they must be in directions where intergalactic absorption by dark matter is minimum, allowing observers to see them.
D) their spectra have not been as redshifted by their motion as those of galaxies and hence they can still be seen.