Which of the following scenarios will ensure that the value of the NEXT_STEPNO column in a given row of table TABLEX exists as a value of column STEPNO (usually in another row) in the same table?（）
- ADefine a UNIQUE constraint on the columns NEXT_STEPNO and STEPNO.
- BDefine a CHECK constraint on the NEXT_STEPNO column (NEXT_STEPNO = STEPNO).
- CDefine column STEPNO as the primary key of TABLEX and column NEXT_STEPNO as a foreign key referencing column STEPNO of the same table.
- DDefine column NEXT_STEPNO as the primary key of TABLEX and column STEPNO as a foreign key referencing column NEXT_STEPNO in the same table.