In the Double-Exhaust Model, the Radio Lobes of a Radio

Multiple Choice

In the double-exhaust model, the radio lobes of a radio galaxy are inflated by

A) jets of excited gas flowing from the central galaxy.
B) jets of high-energy sound waves flowing from the central galaxy.
C) a disk of ionized material that orbits very near a supermassive black hole.
D) dark clouds of very cold gas and dust.
E) None of the other choices are correct.