George is a network administrator at a power plant. He notices that several turbines had unusual ramp-ups in cycles last week. After investigating, he finds that an executable was uploaded to the system control console and caused this. Which of the following would be most effective in preventing this from affecting the SCADA system in the future?

Separating the SCADA (supervisory control and data acquisition) system from the main network makes it less likely that the SCADA system can be affected from the main network. This includes malware as well as human action. Software-defined networking (SDN) would make isolating the SCADA system easier but would not actually isolate it. Patch management is always important, but in this case, it would not have prevented the issue. Encrypted data transmissions, such as TLS, would have no effect on this situation.