Frontline employees who $\_\_\_\_\_\_\_\_,$ advocate the interests and enhance the image of the firm to consumers, and take the initiative to engage in conscientious behavior in dealing with customers can be a critical asset in handling complaints.

a$.$

pay for their own off$-$hours training

b$.$

adopt extra$-$role behaviors

c$.$

role play with customers

d$.$

treat all customers like their own mothers

e$.$

role play with colleagues