Final answer:
The aspect of customer service that Marcus is demonstrating by accepting a longer lead time for quality tires is reliability. He trusts Trenholm's dependable service and understands that it supports a trustworthy reputation for his company.
Step-by-step explanation:
Marcus is demonstrating the importance of reliability in customer service by choosing Trenholm for tire supplies even if it involves a longer lead time. He values the consistent quality and the assurance that he won't have any issues with the order, highlighting trust in the company's dependable service.
This aspect of customer service focuses on the company's ability to deliver what is promised, thus ensuring customer satisfaction and building a strong, trustworthy reputation which is important for long-term success.