You want to mitigate failures that are caused by STF loops that occur before UDLD detects the failure or that are caused by a device that is no longer sending BPOUs. Which mechanism do you use along w

Root guard prevents a port from accepting superior BPDUs that would alter the root bridge election but does not protect against loops caused by a port failing to receive BPDUs.

BPDU guard disables a PortFast-enabled edge port when any BPDU arrives, which is the inverse of this problem - the threat here is BPDUs ceasing, not appearing unexpectedly.

BPDU filtering suppresses BPDU transmission and reception on a port, which would eliminate the STP protection mechanism and actively increase the risk of bridging loops.

Loop guard places a switch port into loop-inconsistent blocking state when expected BPDUs are no longer received, preventing it from transitioning to the forwarding state and forming a bridging loop - this addresses both the window before UDLD detects a unidirectional failure and the case where a device has completely stopped transmitting BPDUs.