What does the speed of light postulate state?
a. Nothing can travel faster than the speed of light.
b. The speed of light in a vacuum, measured in any inertial reference frame, always has the same value of c.
c. The speed of light in a vacuum varies with the wavelength, but is a constant for each wavelength in all reference frames.
d. The speed of light in a vacuum is constant unless the viewer is moving toward or away from the light source.
e. The speed of light depends on the relative velocity of the light source relative to the observer.