Open is a WiFi security option that does not use any encryption or authentication to protect the wireless network from unauthorized access or eavesdropping. Open would create the most need for a VPN connection on the client device because VPN (Virtual Private Network) is a technology that creates a secure and encrypted tunnel between the client device and a remote server over the Internet. VPN would provide an additional layer of security and privacy for the wireless communication that is not provided by the open WiFi network. WEP (Wired Equivalent Privacy), WPA (WiFi Protected Access), and WPA2 (WiFi Protected Access II) are WiFi security options that use encryption and authentication to protect the wireless network from unauthorized access or eavesdropping. WEP, WPA, and WPA2 would create less need for a VPN connection on the client device than open because they already provide some level of security and privacy for the wireless communication. References: CompTIA IT Fundamentals+ Study Guide: Exam FC0-U61, Second Edition, Chapter 8: Security Concepts, page 311.