For a router to obtain a certificate from a CA, what is the first step of the certificate enrollment process?

A.
The router generates a certificate request and forwards it to the CA.

B.
The router generates an RSA key pair.

C.
The router sends its public key to the CA.

D.
The CA sends its public key to the router.

E.
The CA verifies the identity of the router.

F.
The CA generates a certificate request and forwards it to the router.