Final answer:
The licensee should keep the custody of the real estate broker for the benefit of the buyer or seller.
Step-by-step explanation:
In real estate transactions, the licensee (real estate agent or salesperson) should keep custody of the real estate broker's trust account for the benefit of the buyer or seller involved in the transaction.
This is because the broker holds the funds in trust on behalf of the buyer or seller, and it is the licensee's responsibility to ensure that these funds are properly managed and accounted for.
Therefore, the correct answer is 3) The seller, as the licensee should keep custody of the real estate broker's trust account for the benefit of the buyer or seller.