Which of the following is an aspect of after-sales service?

The aspect of after-sales service focuses on the support provided to customers after they have purchased a product or service. This includes various elements aimed at ensuring customer satisfaction and enhancing their overall experience with the company. Customer feedback response is a key component of this aspect, as it involves actively listening to and addressing any concerns, suggestions, or comments from customers regarding their purchase. By responding to customer feedback, businesses can identify areas for improvement, build stronger relationships, and potentially increase customer loyalty.

In contrast, finalization of the deal pertains to the completion of a sale, which occurs before after-sales service begins. Market expansion refers to strategies aimed at increasing a company's footprint and customer base, which does not directly relate to post-purchase support. Product development, while important for creating new offerings, is not an aspect of after-sales service as it typically involves the design and innovation stages before the product reaches the customer. Thus, customer feedback response is integral to maintaining a positive relationship with customers and aligning products with their needs.