You upgraded Oracle Database 10g to Oracle Database 11g. How would this affect the existing users’ passwords？（）  

• A、 All passwords automatically become case-sensitive.
• B、 All passwords remain non-case-sensitive till they are changed.
• C、 All passwords remain non-case-sensitive and cannot be changed.
• D、 All passwords remain non-case-sensitive until their password attribute in the profile is altered.