When it comes to the marketing and logistics interface, what is the main reason for the growing importance of customer service?

a$.$

Customer service is a way to differentiate a company from its competitors.

b$.$

Customer service is more important than product quality.

c$.$

Customer service should be the primary focus of marketing efforts.

d$.$

Logistics can improve customer service delivery.

e$.$

Customer expectations for service have remained constant over time.