Which of the following characteristics describe the Root Guard feature?

Which of the following characteristics describe the Root Guard feature? (Choose all that apply.)
A. The port must be put into forwarding state manually after root-inconsistent state has been corrected.
B. A Root Guard port receiving superior BPDU goes into a root-inconsistent state.
C. A Root Guard port receiving inferior BPDU goes into a root-inconsistent state.
D. While the port is in a root-inconsistent state no user data is sent across that port.
E. The port returns to a forwarding state if inferior BPDUs stop.
F. It should be applied to all switch ports.