Which of the Following Is an Example of Channel Differentiation

Which of the following is an example of channel differentiation?

A) Ritz-Carlton has an intensive training program for its customer-facing employees, to ensure a consistent service standard.
B) Shangri-La hotels use a distinctive signature fragrance in all outlets so that customers can associate the fragrance with the hotel.
C) JEK's sophisticated customer database allows the company to handle queries and product returns much faster than competitors.
D) RTZ shifted its products from supermarket aisles to exclusive stores as it realized that customers were willing to pay more in stores.
E) Hayley's found success by allowing buyers to customize the color and some features of its appliances before buying them.