PRIMARY KEY based on data for an entity

DEPT

DEPTCODE

Information Systems and Operations Management

ISOM

Management

MGMT

Finance

FNAN

Accounting

ACCT

Marketing

MKTG

Business Foundations

BUSF

For an entity DEPARTMENT, both department name and DEPTCODE are both always present and always unique.

Which of the following statements are correct?

Composite of $($DEPT$,$ DEPTCODE$)$ is required to serve as primary key

DEPT is a candidate key

DEPTCODE would be better suited than DEPT as a primary key

DEPTCODE is a candidate key

DEPT would be better suited than DEPTCODE as a primary key