For Which of the Following Reasons Should HR Be Involved

For which of the following reasons should HR be involved with the process of firing an employee?

A) HR is involved to ensure that the situation is handled properly, doesn't escalate, and to mitigate the risk of a retaliatory ex-employee filing a lawsuit.
B) HR is involved to prevent the employee manager from having to face the ex-employee and answer questions about why the firing occurred.
C) HR is involved to ensure that the ex-employee leaves immediately and has no access to speak with employees about any issues.
D) HR is involved to prevent the ex-employee not having access to sabotage the company or steal company property or information.