The Hot Spots in Double-Lobed Radio Source

The hot spots in double-lobed radio source

A) appear to coincide with the location of the central galaxy responsible for the jets.
B) are where hot excited gas interacts with the intergalactic medium.
C) are only found near quasars.
D) produce enough visible energy to be imaged at visible wavelengths.
E) are always perpendicular to each other.