Answer: B. Davisson and Germer
The concept of light being able to propagate through a vacuum was explained in depth by the work of Davisson and Germer. The scientist made use of a vacuum apparatus which was designed by them. The role of this apparatus was to measure the electron energy which was scattered from a surface comprising of metal. They are made of a voltage to accelerate the electron generated from a heated light source. The voltage was the target at a metal made of nickel. Their observation included the fact that the intensity of the electron beam which was scatter peaked at a certain angle and they also record the performance at other angles. The peak point showed the wave pattern for the electrons