John is the Broker-in-Charge for Best Yet Realty. He takes a listing at 123 Main Street for $475,000 with the seller authorizing both dual and designated agency. Mary is an agent with Best Yet Realty and is working with a buyer that wants to make an offer on the home. Mary's client has authorized both dual and designated agency. Under the following scenario, which of the following statements is FALSE?
a) The listing firm can act as both dual and designated agent.
b) Mary, the agent, can represent both the buyer and the seller as a designated agent.
c) Dual agency is prohibited in this situation.
d) Both the buyer and the seller must consent to dual agency.