Which PL/SQL package would you use?

You explicitly specified the tablespace usage threshold values while creating a tablespace. You need to revert the database-wide default tablespace usage threshold values for the tablespace.
Which PL/SQL package would you use?

A.
DBMS_STATS

B.
DBMS_ALERT

C.
DBMS_SPACE

D.
DBMS_MONITOR

E.
DMBS_SERVER_ALERT

F.
DBMS_SPACE_ADMIN

Explanation:
Explanation :
The DBMS_SERVER_ALERT package contains a number of procedures that allows you to set, view and modify a variety of alert conditions. There are three procedures available in the package which are SET_THRESHOLD
GET_THRESHOLD
EXPAND_MESSAGE
The SET_THRESHOLD procedure is used set/revert to required threshold values.
e.g.
SQL> execute
dbms_server_alert.set_threshold(
dbms_server_alert.tablespace_pct_full,
dbms_server_alert.operator_ge, 85,
dbms_server_alert.operator_ge, 99,
1,1, null,
dbms_server_alert.object_type_tablespace, ‘ USERS’) ;
The new threshold goes into effect immediately. The next time MMON process runs, an alert will be generated if the space usage on the USERS tablespace is 85% or higher.