Dion Training has an open wireless network called "InstructorDemos" for its instructors to use during class, but they do not want any students connecting to this wireless network. The instructors need the "InstructorDemos" network to remain open since some of their IoT devices used during course demonstrations do not support encryption. Based on the requirements provided, which of the following configuration settings should you use to satisfy the instructor's requirements and prevent students from using the "InstructorDemos" network?
1) Signal strength
2) QoS
3) NAT
4) MAC filtering