Which of the following responses is not appropriate when greeting a customer?

The response "I'm too busy right now" is not appropriate when greeting a customer because it conveys a sense of disinterest and unavailability, which can negatively impact the customer’s experience. Customer service interactions are vital for building rapport and ensuring customers feel valued and welcomed. A warm greeting should exhibit readiness to assist and attentiveness to the customer's needs.

In contrast, the other responses encapsulate a positive customer service attitude. "Welcome to Domino's!" invites the customer into the experience, setting a friendly tone. "Thank you for calling Domino's" acknowledges the customer’s action and expresses appreciation, enhancing their interaction. "How may I help you?" directly addresses the customer's needs and shows a willingness to assist, both of which are essential qualities in effective customer service.