When using public Wi-Fi networks (e.g., in a cafe or airport), which security measure is most important to protect your personal data from potential eavesdropping?

✓ Correct Answer: Option B

A Virtual Private Network (VPN) encrypts your internet connection, creating a secure tunnel for your data, which is crucial when using unsecured public Wi-Fi networks where malicious actors might try to intercept your information. Visiting only "http://" websites is incorrect; you should prioritize "https://" for secure connections.