Hello adjacency will be brought up using link Hello packet with source IP address set to the interface borrowed IP address and a destination IP address set to 224.0.0.2.
By default, the LDP session uses the system interface address as the LSR-ID unless explicitly configured using the command config>router>ldp>interface-parameters>interface>local-lsr-id interface. Using this command user is allowed to use the local interface as both the LSR-ID and the transport address for the link-level LDP session. Note that when the interface option is selected, the transport connection (TCP) for the link LDP session will also use the address of the local LDP interface as the transport address. If system is the value configured under the command configure>router>ldp>interface-parameters>interface>transport-address, it will be overridden.
The LSR with the highest transport address, that is, LSR-ID in this case, will bootstrap the TCP connection and LDP session.
Source and destination IP addresses of LDP packets are the transport addresses, that is, LDP LSR-IDs of systems A and B in this case.