假设用户正在执行UPDATE操作，此时用以下哪种方法可以关闭数据库（）
- ASHUTDOWN或SHUTDOWN IMMEDIATE或SHUTDOWN ABORT
- BSHUTDOWN或SHUTDOWN NORMAL或SHUTDOWN TRANSACTIONAL
- CSHUTDOWN NORMAL或SHUTDOWN ABORT或SHUTDOWN IMMEDIATE
- DSHUTDOWN或SHUTDOWN IMMEDIATE或SHUTDOWN TRANSACTIONAL
- ESHUTDOWN ABORT或SHUTDOWN IMMEDIATE或SHUTDOWN TRANSACTIONAL