Which two statements describe the authentication method used with Cisco Intersight REST API Requests?

Which two statements describe the authentication method used with Cisco Intersight REST API Requests? (Choose two.)
A. The REST API request contains a base64-encoded signature of the message content and headers.
B. The REST API request message body is encoded as a SHA384 hash and then signed with the API Key ID.
C. The Cisco Intersight Web service verifies the signature of incoming request with the RSA public key for the API Key ID.
D. The incoming REST API request is challenged by the Cisco Intersight Web service with a request for the RSA private key.
E. The message body is encoded as a SHA256 hash if the message body is not empty and then signed with the API Key ID.