An electromagnetic wave travels in a vacuum. The wavelength of the wave is tripled. How is this accomplished? by tripling the frequency of the wave by tripling the magnitudes of the electric and magnetic fields that comprise the wave by reducing the frequency of the wave by a factor of three by reducing the speed of the wave by a factor of three by tripling the speed of the wave

by reducing the frequency of the wave by a factor of three

Explanation:

Speed = wavelength * frequency.

Wavelength = speed/frequency

The speed of an electromagnetic wave in a vacuum is constant. Meanwhile the wavelength and frequency have an inverse relationship which means for every rise in any of the parameters there will also be a corresponding fall.

Since the wavelength is tripled then the frequency will also be reduced by a factor of 3