Which Description of the The OceanStor V3 File System Snapshot

Which description of the the OceanStor V3 file system snapshot feature is wrong?

A) In File System Snapshot when you create a snapshot, you simply copy the root of the file system and save it to form a snapshot of the file system.
B) Deletion Snapshots use a mechanism for reclaiming space, so snapshot data space is immediately freed after snapshots have been deleted.
C) After creating a snapshot in the File System, as the main file system is continuously updated, the original data block will gradually become the space occupied by this quick debt. However, a newly written data will not be included in the snapshot space.
D) File system snapshot data can not be deleted directly, and only after the snapshot has been deleted, this part of the space can be released.