Complainants have the ultimate responsibility ("burden") of:

The correct choice indicates that complainants have the ultimate responsibility of proving that the code of ethics has been violated. This is a fundamental principle in ethical disputes and legal proceedings, where the burden of proof lies with the party making the allegations. In the context of real estate, when a complainant believes that a Realtor® has acted unethically, it is their duty to present sufficient evidence to support their claims. This process ensures that ethical standards are upheld and that the decision-makers have a clear basis for judgment.

In contrast, providing legal representation is generally the responsibility of the complainant’s legal counsel, should they choose to seek one. Settling the dispute before arbitration often involves negotiation and mediation but is not exclusively the complainant's responsibility, as it can also depend on the willingness of the other party involved. Confidentially reporting concerns may be encouraged in some instances, but it does not serve to satisfy the necessary requirement of demonstrating a violation. Thus, the core obligation of proving a violation of the code of ethics clearly falls to the complainant.