Database systems that store each relation in a separate operating system file may use the operating system’s authorization scheme, instead of defining a special scheme themselves. In this case, which of the following is false?

• A. The administrator enjoys more control on the grant option.
• B. It is difficult to differentiate among the update, delete and insert authorizations.
• C. Cannot store more than one relation in a file.
• D. Operations on the database are speeded up as the authorization procedure is carried out at the operating system level.