Answer:
The answer would be Option D. Discuss the situation with your Ethics Officer if you have one, but this position is rare in most companies and firms.
Explanation:
If the goal is to increase workplace ethics and to make the workplace an ethical place, then you should very diplomatically try to say you feel there was some favoritism in being passed over for the position. But first you should evaluate whether the promotion really was due to favoritism because maybe the candidate did work harder or provided some other kind of objective advantage that does make them right for the job. You also should not blame the other candidate who did get the promotion if you value your work relationships and want to continue to be a part of the company. It is important to establish an ethical framework in organization because if coworkers are not treated equally this can foster a sense of resentment and de-motivate employees. If there is no neutral party like an ethics officer at your firm then speaking to human resources or your supervisor may be in order, but there are risks as coming across as resentful.