An RSA key pair consists of a public key and a private key and is used to set up PKI.
Which statement applies to RSA and PKI?

A.
The public key must be included in the certificate enrollment request.

B.
The RSA key-pair is a symmetric cryptography.

C.
It is possible to determine the RSA key-pair private key from its corresponding public
key.

D.
When a router that does not have an RSA key pair requests a certificate, the
certificate request is sent, but a warning is shown to generate the RSA key pair before a
CA signed certificate is received.

Explanation:
An RSA key pair consists of a public key and a private key. When setting up your PKI, you
must include the public key in the certificate enrollment request. After the certificatehas been granted, the public key will be included in the certificate so that peers can use
it to encrypt data that is sent to the router. The private key is kept on the router and
used both to decrypt the data sent by peers and to digitally sign transactions when
negotiating with peers.
http://www.cisco.com/c/en/us/td/docs/iosxml/ios/sec_conn_pki/configuration/xe-3s/sec-pki-xe-3s-book/sec-pki-overview.html