What is true about Unicast RPF in strict mode？（）

• A、It works well with a multihomed environment.
• B、It will inspect IP packets that are encapsulated in tunnels， such as GRE，LT2P，or PPTP.
• C、uRPF is performed within the CEF switching path.
• D、There might be a problem with DHCP as Unicast RPF is blocking packets with a 0.0.0.0 sourceaddress.