Which three statements about OCSP are correct? (Choose three.)

A.
OCSP is defined in RFC2560.

B.
OCSP uses only http as a transport.

C.
OCSP responders can use RSA and DSA signatures to validate that responses are from
trusted entities.

D.
A response indicator may be good, revoked, or unknown.

E.
OCSP is an updated version SCEP.