Horch is the biggest manufacturer of consumer goods in Germany. The company segments its business customers into new and existing customer groups based on the stage of relationship between the company and the customer. This helps the company to develop different strategies for newly acquired customers and the existing customers, who are interested in making repeat purchases. Which of the following segmentation approaches is being used by Horch in the above scenario?
a. Segmentation by customer type
b. Segmentation by purchase categories
c. Segmentation by end-use application
d. Segmentation by demographic characteristics