A Radio Ad by the Dairy Farmers of Washington State

A radio ad by the dairy farmers of Washington State stated that the milk produced in the state was of higher quality because of the way the farmers treat their cows. They said that the difference comes from how comfortable they make their cows. Among others, this differentiation could certainly appeal to animal lovers and those moving toward organic products. This is an example of ________.

A) personnel differentiation
B) channel differentiation
C) service differentiation
D) product differentiation
E) image differentiation