The digital signature of a patch provides an integrity check of the patch. Which is a requirement for signed patches?

A.
The system administrator needs to sign the patch.

B.
All patches need to be signed by Sun Microsystems.

C.
Signed patches need to be downloaded through SSL.

D.
Vendors can sign patches only with approval from Sun Microsystems.

E.
The system administrator can specify which Certification Authorities are trusted for signed patches.