Using Maxwell's Equations It Can Be Shown That Electromagnetic Waves

Multiple Choice

Using Maxwell's equations it can be shown that electromagnetic waves have a speed in free space of

A) (ε_Oμ_O) ^-3/2.
B) (ε_Oμ_O) ^-1/2.
C) ε_Oμ_O.
D) (ε_Oμ_O) ^-2.
E) (ε_Oμ_O) ^-1.