Which of the following statements about the link failure detection in STP protocol is not true? 

When network topology is stable, the Designated Port sends BPDU packet at every Hello Time interval. 

When network topology is stable, BPDU packets will be transmitted periodically. 

When the port does not receive new BPDU within a certain interval, the old configuration BPDU will time out and the link failure can be detected. 

The port sends Configuration BPDU at every Hello Time interval. When the link fails, Configuration BPDU cannot be sent out. As a result, this port can detect the link failure.