Joe, a technician at the local power plant, notices that several turbines had ramp up in cycles during the week. Further investigation by the system engineering team determined that a timed .exe file had been uploaded to the system control console during a visit by international contractors. Which of the following actions should Joe recommend?
A. Create a VLAN for the SCADA
B. Enable PKI for the MainFrame
C. Implement patch management
D. Implement stronger WPA2 Wireless