Cullumber, Inc. is a consulting firm headquartered in Dallas. Trish Hardin, CEO of the company plans to attend a professional conference in Atlanta where she intends to network in the pursuit of business. She enjoys shopping and dining in Atlanta and is looking forward to the trip. She registered for the conference and made hotel and airfare reservations six weeks ago. Her airline ticket and registration fee are non-refundable, but it is not too late to cancel her hotel room. The day before the conference, a company executive from El Dorado calls and wishes to meet with Trish the next day regarding a consulting project. If Trish chooses to make the trip to El Dorado, she will drive. Both trips will require an overnight stay. Trish does not have a prediction of how much revenue either trip may generate. Costs related to the two trips are as follows: (a) Which of the above costs are not relevant