What are the "bound IP addresses" used for in LDP？（）

A.For each such address and mask /32, one label binding is created.
B.As the TCP endpoint, IP addresses are used by the LDP session.
C.These addresses are used to find the label binding to put in the LFIB, by looking up these IP addresses in the routing table.
D.These addresses are used for penultimate hop popping (PHP) when forwarding packets to the next router directly.