Which statements are true regarding SecureFile LOBs?（）

• A、The amount of undo retained is user controlled.
• B、SecureFile LOBs can be used only for nonpartitioned tables.
• C、Fragmentation is minimized by using variable-sized chunks dynamically.
• D、SecureFile encryption allows for random reads and writes of the encrypted data.
• E、It automatically detects duplicate LOB data and conserves space by storing only one copy.