Under which of the following circumstances has a North Carolina listing broker violated their agency relationship with a seller-client? A. The listing broker presents the seller with an offer after a contract is pending on the listed property. B. The listing broker presents the seller with an offer three (3) days after receiving it from the buyer agent. C. A broker employed by the listing broker presents an offer from their sister and her spouse without disclosing the relationship. D. The listing broker presents the seller with a low price offer and, at the same time, tells the seller that a higher offer from a different buyer is expected