Which of the Following Is a Difference Between Customers and Clients

Which of the following is a difference between customers and clients in the context of relationship marketing?

A) Customers have identities and names,while clients do not.
B) Customers have no strong reason to feel allegiance to a service provider,while clients often have a strong relationship with the service provider.
C) Customers are individual entities,while clients are reflected in market summaries as mere numbers and data entries.
D) Customers are served on an individual basis,while clients are mass target groups.