Tiffany Jewelers does not set the price of its diamonds too low. Tiffany Jewelers does this because it realizes that most consumers find it hard to assess the objective quality of diamonds and hence the higher the price of a diamond, the higher its perceived quality. This is an example of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

a$.$ acceptable cost

b$.$ perceptual investment

c$.$ price$-$quality heuristic

d$.$ return on investment

e$.$ barter potential