Examine the commands executed in the following sequence： 1：SQL> CREATE ROLE mgrrole； 2：SQL> GRANT create user，select any table，connect，resource TO mgrrole； 3：SQL> GRANT select，update ON sh.sales TO mgrrole； 4：SQL> CREATE ROLE ceo IDENTIFIED BY boss； 5：SQL> GRANT mgrrole，drop any table，create any directory TO ceo； 6：SQL> GRANT ceo TO mgrrole； Which statement is true about the above commands（）
A、The commands execute successfully.
B、Command 6 produces an error because of circular role grant.
C、Command 5 produces an error because a role cannot be granted to another role.
D、Command 3 produces an error because the MGRROLE role already contains system privileges.
E、The table created by HR remains and HR still has the CREATE TABLE system privilege.
F、The table created by HR remains and HR can grant the CREATE TABLE system privilege to other users.
