How Do Employers Protect Assets with Security Policies Pertaining to Employee

How do employers protect assets with security policies pertaining to employee surveillance activities?

A) Employers promote monitoring activities of employees as long as the employees demonstrate trustworthiness.
B) Employers use informal verbal communication channels to explain employee monitoring activities to employees.
C) Employers use network surveillance to monitor employee email traffic, network access, and to record employee keystrokes.
D) Employers provide employees written statements that clearly discuss the boundaries of monitoring activities and consequences.