An Isilon Customer Created a SyncIQ Policy to Replicate Data

An Isilon customer created a SyncIQ policy to replicate data from a primary cluster to an offsite secondary cluster. The primary cluster becomes unavailable, and the customer has completed a failover onto the secondary cluster. The primary cluster becomes available again, so the customer would like to fail back data to the primary cluster. The failback process does not replicate data. What is the most likely reason the failback policy does not replicate data to the primary cluster?

A) Clusters are not sharing an Infiniband switch
B) Secondary cluster has modified files on it
C) Original policy was for synchronization
D) Policy contains a SmartLock directory