Answer:
The correct answer is "b) counteroffer"
Explanation:
In other words, a counteroffer is an "offer made in response to another"
For Don´s case, if the employers don´t make a counteroffer, Don would leave the company (for the benefits that the rival is offered). If you were a manager, and you appreciate his work, the right decision is "Don's employers decided to make him a counteroffer matching the offer from their rival firm ".
