Correct Answer: B,D
YANG data models are designed to define the structure of network configuration and state data. They include:
* rpc statements: These define remote procedure calls that can be invoked on network elements via management protocols like NETCONF.
* container statements: These define hierarchically structured containers of data, which can hold other data elements such as leafs, lists, and additional containers.
YANG is a modular language that represents data structures in an XML tree format, and it is protocol-independent, meaning it can be converted into any encoding format like XML or JSON that the network configuration protocol supports. It also allows for the use of XPATH expressions to define constraints on the elements of a YANG data model.