What lesson can be best learned from the stories of Chinese restaurant and the European ca

What lesson can be best learned from the stories of Chinese restaurant and the European car manufacturer？

A．To retain customers, service should be improved.

B．Good quality of product is the most important.

C．Customer needs should be the primary concern.

D．Good service and quality can make customers satisfied.

请帮忙给出正确答案和分析，谢谢！