正解:C
To enable router R2 to be configured via NETCONF, the necessary command set is found in Option C.
NETCONF is a network management protocol developed and standardized by the IETF. It allows for the installation, manipulation, and deletion of the configuration of network devices. The commands in Option C are designed to start the NETCONF server on the device and open the required NETCONF session over SSH, which is the standard transport for NETCONF.