Final answer:
The seller's agent should provide written notice to Ahmad and Mahasin in the form of a counteroffer. Correct option is 1)
Step-by-step explanation:
The seller's agent should provide written notice to Ahmad and Mahasin.
This written notice is usually in the form of a counteroffer, which outlines the changes the seller is willing to make to the initial offer. The agent should communicate the seller's rejection of the offer and provide the counteroffer to Ahmad and Mahasin.
By providing written notice, both parties have a clear understanding of the seller's decision and can negotiate further if desired.