Final answer:
A salesperson should show different band options and assist in choosing one when a customer wants a band change for a watch they like.
Step-by-step explanation:
When a customer wants a band change for a watch they like, the appropriate response for a salesperson would be to show different band options and assist in choosing one (c).
By offering various band options and helping the customer in making a decision, the salesperson is providing a personalized experience and showing a willingness to accommodate the customer's preferences. This approach can lead to customer satisfaction and potentially increase sales.
On the other hand, options a, b, and d are not the optimal responses because they limit the customer's choices, do not provide adequate assistance, or discourage a potential sale.