which is sometimes used to prevent loops in the MPLS domain?

What is true about the "path vector" TLV which is sometimes used to prevent loops in the MPLS domain?

A.
It is supported by LDP and TDP.

B.
It operates in a similar fashion to BGP’s AS-Patch facility.

C.
The TLV holds the ID’s of all ATM LSR’s in the MPLS path.

D.
If an LSR receives an LDP update which contains its own ID the update is dropped.