Which Description Is True About Downstream Suppression

Which description is true about downstream suppression?

A) the ability of a fault management tool to generate alerts for only an upstream device failure and to suppress the alarms related to all unreachable downstream sites
B) the ability of a router to suppress downstream route fluctuations to avoid introducing instability into the network core
C) the ability of a network management station to perform root cause analysis on a network fault and remove duplicates of all other alarms resulting from fault symptoms
D) the ability of an element manager to restrict forwarding to critical performance alarms northbound to the Manager of Managers and suppress other alarms