The Synchrotron Radiation (Radio Waves) That Astronomers First Observed from Jupiter

The synchrotron radiation (radio waves) that astronomers first observed from Jupiter in the 1950's comes from:

A) deep within Jupiter, in the metallic hydrogen layers
B) high speed electrons spiraling around the planet's strong magnetic field
C) the upper-atmosphere clouds that move so quickly near the equator of the planet
D) the Red Spot with its tremendous friction
E) physics labs at the University of Jupiter, on the planet's surface