A previously functional, scheduled snapshot operation against a JFS2 filesystem has failed. The JFS2 filesystem is mounted and appears intact. What is the most likely cause of the failure and how should it be resolved?（）

A. The associated JFS2 log device has failed. Check the log device and varyon the device.
B. The logical volume that hosts the snapshots is full. Increase the size of the logical volume.
C. Fifteen snapshots already exist for the given JFS2 filesystem. Delete at least one existing snapshot.
D. The volume group that hosts both the snapshots and JFS2 filesystem has lost quorum. Check and correct the integrity of the volume group.