The answers are "B" and "D". https://ftp.ripe.net/rfc/v3test/test8345.v2v3.html "8. Security Considerations The YANG modules specified in this document define a schema for data that is intended to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC5246]."

B & D Study Guide Data Models and Supporting Protocols This section gives a high-level overview of some of the most common data models and tools and how they are used in a programmatic approach: Yet Another Next Generation (YANG) modeling language Network Configuration Protocol (NETCONF) , defined in RFC 4741 and RFC 6241, is an IETF standard protocol that uses the YANG data models to communicate with the various devices on the network. RESTCONF , defined in RFC 8040, is used to programmatically interface with data defined in YANG models while also using the datastore concepts defined in NETCONF.

restconf along with netconf