Wavelength Is Defined How, in Terms of Electromagnetic Radiation

Multiple Choice

Wavelength is defined how, in terms of electromagnetic radiation?

A) The peak to peak distance between waves.
B) The peak to trough distance between waves.
C) The speed with which a wave traverses a distance.
D) The amplitude with which a wave traverses a distance.
E) The trough to peak distance between a wave as well as the speed the wave traverses this distance.