Electromagnetic Radiation Moving Through Space with the Speed of Light

Electromagnetic radiation moving through space with the speed of light consists of oscillating:

A) electric and magnetic fields moving in opposite directions along the same line in space.
B) magnetic fields that, over time and distance, change to oscillating electric fields and then back to magnetic fields in a continuous manner.
C) electric and magnetic fields, always inseparable, always having the same frequency and wavelength and traveling in the same direction.
D) electric fields, with magnetic fields occasionally accompanying them, moving in the same direction.