Which of the following statements about the main and backup channels of optical line protection is wrong?

Which of the following statements about the main and backup channels of optical line protection is wrong?
A . "Initial Difference Between Active and Standby Channels (dB)"―the reference value used to set the optical power difference between the active and standby channels of the board.
B. "Master-standby channel difference threshold (dB)" – used to set the difference between the main and standby optical ports of the board when the optical power difference reaches a certain value, it will be regarded as a signal failure (SF).
C. When the difference in the optical power of the full backup exceeds the threshold, the optical switch will switch the service to the backup channel, and the set value supports query. Recommended setting is 5dB
D. If the current optical power difference between the active and standby channels exceeds the "main and standby channel difference threshold (dB)", the system will initiate protection switching.

Answer: C