Light is an electromagnetic wave and can travel through a vacuum. There is a constant that appears in formulae which involve magnetism and is denoted by the letter μ₀ "mu zero", whilst in electrostatic formulae another constant ε₀ "epsilon zero" will appear.
The speed of light in a vacuum is given by c=ε0μ01.
The units of ε₀ are N⁻¹ C² m⁻²
The units of μ₀ are:
A. kg⁻¹ m⁻¹ C²
B. kg m C⁻²
C. kg m s⁻⁴ C⁻²
D. kg⁻¹ s⁻³ C⁻²