Answer: b. Rejected the offer and made a counteroffer.
Step-by-step explanation:
When Bill told Dina that the price for the business was $100,000, Dina replied that the prices was too high. This constitutes a rejection to buy at that price.
Dina then offered to buy the business at the price of $90,000 which constitutes a counteroffer. Dina therefore rejected the original offer and made a counteroffer.