Select all that apply

Which examples demonstrate explicit communication rules?

Multiple select question.

a$.$ A manager instructs the company's receptionist to greet every customer with, "Hello! How may I help you?"

b$.$Kathy's co$-$worker tells her that she should speak up more often during staff meetings.

c$.$ A bank forbids its employees from discussing their customers outside of the work environment.

d$.$ Someone on the sales team advises a colleague to compliment customers on their clothing or hair style.