Devon Degosta is updating the employee database with information on a new employee. She enters the employee information into the employee table and then tries to add a department ID for a department that does not exist in the Departments table. The system does not allow her to add the employee record until she creates a Department ID first in the Department table so the employee can then be assigned to it. This is an example of the system enforcing a ________.
a) Data integrity constraint
b) Data security protocol
c) Data normalization technique
d) Data encryption standard
