Evaluate the set of SQL statements: CREATE TABLE dept (deptno NUMBER(2), dname VARCHAR2(14), loc VARCHAR2(13)); ROLLBACK; DESCRIBE DEPT What is true about the set?（）
- AThe DESCRIBE DEPT statement displays the structure of the DEPT table.
- BThe ROLLBACK statement frees the storage space occupied by the DEPT table.
- CThe DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist.
- DThe DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.