As an HR Professional, You Must Sometimes Terminate Employees from Your

As an HR Professional, you must sometimes terminate employees from your organization. When an employee is terminated, there must be a just cause or a good cause for the termination. Which one of the following is not a valid just cause for the employee's termination?

A) Whether reasonable "proof" of the violation existed, or was obtained through investigation
B) Whether the employee was warned in advance
C) Whether the rule has been applied consistently
D) Whether the employee is a member of a protected class