Final answer:
When a beam of light approaches the event horizon of a black hole, it bends and becomes redshifted due to the black hole's strong gravitational field.
Step-by-step explanation:
As a beam of light is directed closer to the event horizon of a black hole, several phenomena occur due to the intense gravitational field. The light does not slow down since its speed remains constant in a vacuum, but from the point of view of an external observer, it appears to bend and becomes increasingly redshifted.
This redshift happens because the gravitational field stretches the wavelength of the light, making it shift towards the red end of the spectrum. Additionally, as light gets closer to the event horizon, it will bend more and more due to the warping of spacetime until it potentially becomes trapped, making it appear as though it disappears.
Therefore, the correct answer to what happens as a beam of light is directed closer to the event horizon of a black hole is c) It bends and becomes redshifted.