Under agency law in Virginia, dual agency is:

Agency relationships form the foundation of real estate transactions, defining the legal obligations and duties between agents and clients. This question addresses dual agency, a complex situation that can arise when a real estate firm represents both the buyer and seller in the same transaction. Understanding this concept matters because it directly impacts agent responsibilities, potential conflicts of interest, and legal compliance. The question tests knowledge of Virginia's specific requirements for dual agency, which requires written consent from all parties involved. The reasoning process involves recognizing that agency relationships create fiduciary duties (loyalty, confidentiality, obedience, disclosure, accounting, and reasonable care) that cannot be fully maintained when representing both sides. Option A is incorrect because dual agency isn't inherently illegal in Virginia. Option B is incorrect because consent from just one party is insufficient. Option C is incorrect because broker consent alone doesn't satisfy the requirement. Option D is correct because Virginia law requires written consent from all parties involved, ensuring transparency and acknowledging the potential conflict of interest. This question challenges students because it requires understanding both the general principles of agency relationships and the specific state regulations that modify those principles.