What’s that buzzing noise?

One of your file servers has started making a loud buzzing sound. The buzzing doesn’t ever stop, and it sounds like a game show buzzer when you get a question wrong. What is the most likely cause of this noise?

A) The hard drive is faulty

B) An internal hardware sensor has identified a problem

C) The video hardware has failed

D) A Windows service has failed

E) The server is moonlighting as a lighthouse