Final answer:
A broker acting as a dual agent should not reveal the seller's lowest price, the buyer's maximum budget, or any confidential information about the parties involved to maintain fair dealings and respect confidentiality.
Step-by-step explanation:
When a broker is acting as a dual agent in a real estate transaction, they have a fiduciary duty to both the buyer and the seller. Therefore, certain information must remain confidential to maintain fair dealings.
Among the options provided, Option 2: The seller's lowest acceptable price, and Option 3: The buyer's maximum budget for the purchase are pieces of information that should not be revealed by the dual agent. This is because disclosing these details could undermine the negotiating position of the respective parties.
Option 4: Any confidential information about the parties involved also should not be disclosed, as it pertains to the privacy and agreed upon confidentiality of both parties.