Correct Answers: A, C

Explanation:
The Point-to-Point Protocol (PPP) provides a standard method for transporting multi-protocol datagrams over point-to-point links. PPP was originally emerged as an encapsulation protocol for transporting IP traffic between two peers. It is a data link layer protocol used for WAN connections.
DSL is also considered a WAN connection, as it can be used to connect networks, typically when used with VPN technology.