An HP IRF virtual switch with two members is implementing TRILL. The administrator wants to ensure that the master can fail without causing topology changes or changes in forwarding tables in the TRILL region. Which setting helps support this requirement?
A. Graceful Restart for TRILL
B. Bidirectional Forwarding Detection (BFD) Multi-Active Detection (MAD) for the IRF link
C. calculation of at least two trees
D. non-stop-forwarding for TRILL