Final answer:
Misty's best response to help the customer who requires installation services for a washer-dryer is to offer a list of recommended third-party installers and provide guidance on selecting a reliable service, which would reassure the customer.
Step-by-step explanation:
The best response Misty can offer to reassure the customer who requires installation services would be Option 2: Offer to provide a list of recommended third-party installation services. This approach shows that Misty acknowledges the customer's needs and provides a helpful solution despite the store's limitations. Additionally, to further reassure the buyer, Misty could explain any guarantees or return policies that might apply to the washer-dryer combo to ensure that the customer feels supported in their purchase decision. Furthermore, Misty might provide guidance on what to look for in a good installation service, such as licensure, insurance, and customer reviews, which helps the customer make a more informed choice.