The diagram below shows an experiment designed by a student to observe the effect of bombarding electrons against a metal target. Diagram showing a metal wire on the left which has been shaped into a coil, a metal target is shown on the right side of the diagram with an electron between the coil and the metal target. A wave is also labeled on the diagram near the target and moving in a diagonal or downward motion.

What does the student's experiment most likely demonstrate?

high speed electrons can produce longitudinal waves
electrons are transformed into waves upon striking a metal target
the direction of electromagnetic waves is always towards the pull of gravity
an electromagnetic wave travels perpendicular to the direction of electric field