Which of the following is not a trigger condition for the automatic switching of client...

Among trigger conditions for automatic switching in client 1+1 protection, (A) is false. When SD (Signal Degrade) is disabled, the OTU board does not report an ODUk_PM_DEG alarm as a trigger for switching. Other triggers like the OTU board not detected, OTUk_LOF alarm, and R_LOS alarm reported by OLP or DCP boards are valid triggers for switching. This behavior prevents unnecessary protection switching when SD monitoring is disabled, which helps avoid service disruptions. HCIP-Transmission explains these nuances in protection switching logic to optimize network resilience and reliability.