Answer:
D. Customer service
Step-by-step explanation:
Customer service refers to taking care of customer's needs by rendering high-quality, professional, and useful assistance at all times. It involves ensuring that the customer's needs are met timely and in a manner that reflects the business's positivity.
The customer service department is the unit tasked in ensuring that any arising issues are dealt with promptly. The department helps customers use the purchased products and services to the customers' satisfaction.