Quasars, Double-Radio Sources, and BL Lacertae Objects May Well Be

Multiple Choice

Quasars, double-radio sources, and BL Lacertae objects may well be the same kind of object. The different appearance of them being simply that

A) their position in the universe is different: Quasars are in the Milky Way Galaxy, double-radio sources are associated with other galaxies, and BL Lacertae objects are in the vast voids of space between galaxies.
B) the orientation of Earth's line of sight to the axis of their ejected jets of matter is different.
C) their ages are different: BL Lacertae objects evolving through the double-radio source phase end as quasars.
D) their sizes are different: Quasars are star-sized, double-radio sources are larger, and BL Lacertae objects are galaxy-sized.