The district manager of a boat rental company set a goal to increase customer satisfaction ratings. To achieve this goal, she authorized sales associates to provide customers with additional price discounts. Ten percent of its customers received deep price discounts yet were still not satisfied. This group of dissatisfied and unprofitable customers represents the company$$s $\_\_\_\_\_\_\_\_\_\_.$

a$.$

vulnerable customers

b$.$

dealers

c$.$

star customers

d$.$

free riders

e$.$

lost causes