Refer to the following table diagram:

F The Course table has columns DepartmentCode,

CourseNumber,

CourseName U$,$ CreditQuantity R$,$

and CatalogCode R U$.$

$($DepartmentCode$,$ CourseNumber$)$ is the primary key.

The table is implemented with the following statement:

CREATE TABLE Course $($

DepartmentCode CHAR$(3),$

CourseNumber INT,

CourseName VARCHAR$(30)\_\_$A$\_\_,$

CreditQuantity TINYINT $\_\_$B$\_\_,$

CatalogCode CHAR$(3)\_\_$C$\_\_,$

$\_\_$D$\_\_($DepartmentCode$,$ CourseNumber$)$

$)$;

$1)$

What is A$?$