Which of these choices correctly describe denial-of-service (DoS) attacks?

Which of these choices correctly describe denial-of-service (DoS) attacks? (Choose THREE.)

A.
DoS attacks do not require attackers to have any privileges on a target system.

B.
DoS attacks are nearly impossible to stop, once they begin.

C.
DoS attacks free the target system of excessive overhead.

D.
DoS ties up a system with so many requests, system resources are consumed, and performance degrades.

E.
DoS attacks cause the attacked system to accept legitimate access requests.