Answer:
Here the best suited brokerage relationship for the couple would be with transaction broker , because in this type of relationship buyer or seller would not be responsible for the acts of licensee.
Step-by-step explanation:
A transaction broker is that broker who acts as mutual resource in the real estate transactions, as the they don't represent both neither of the party ( buyer and seller ) , but instead they provide all the information and advice to the buyers and sellers. So therefore for the couple wanting to invest in residential property , the transaction broker would be best.