A negotiator decides to utilize the "Reduce $/$ Increase and Split the Difference" strategy in a negotiation. Her first offer on a car was $$26,000,$ and the owner countered with an offer of $$30,000.$ The negotiator decided to use the strategy and said "I'll increase my offer by $$1,000$ IF you will agree to equally split the remaining $$3,000$ difference". The seller agreed and the deal was settled at $$28,500.$ What advantage of the strategy likely influenced the owner to accept the buyer's last offer?

The social norm of fairness $($in splitting the difference$)$ was involved in the offer.

All of the above.

The offer contained both an increase and an agreement to split the difference in the same offer.

The buyer was increasing the value of the counter by $$1,000$ in addition to then splitting the difference thus employing the equality norm..