Answer:
A. to instruct another broker to negotiate an offer with the sellers on his behalf
Explanation:
Brokers job includes facilitation of a variety of business transactions, such as real estate deals, by acting as a middle man between the parties involved. The broker acts as an agent for the client and charges the client certain amounts for his service.
By law a broker can not ask another broker to help him negotiate an offer. All other options in the question are duties of the broker