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.