What is the role of Forwarding Equivalence Class （FEC） in MPLS？（）

• A、FEC determines how IP packets are forwarded in MPLS LSP.
• B、FEC determines how to establish an LSP path.
• C、FEC determines how a group of IP packets are mapped to an LSP.
• D、FEC determines how MPLS labels are stacked in LSP.
• E、None of above.