Explanation: Incorrect answer: BCD
The CAPF enrollment process is as follows:
1. The IP phone generates its public and private key pairs.
2. The IP phone downloads the certicate of the CAPF and uses it to establish a TLS session with the CAPF.
3. The IP phone enrolls with the CAPF, sending its identity, its public key, and an optional authentication string.
4 . The CAPF issues a certicate for the IP phone signed with its private key.
5 . The CAPF sends the signed certicate to the IP phone.
Link:
http://my.safaribooksonline.com/book/certification/cipt/9781587052613/understanding- cisco-ip-telephony-authentication-and-encryption-fundamentals/584.