Answer:
a. following-up with his customer.
Step-by-step explanation:
Based on the scenario being described within the question it can be said that Lewis is following-up with his customer. This is when a salesperson contacts a customer some time after their purchase in order to make sure that they are happy with their purchase. This allows the salesperson to address any problems or concerns that the customer may have with their product. All with the goal of trying to capture the loyalty of the customer, since a customer that is happy with an initial purchase is more likely to return.