When using public Wi-Fi networks (e.g., in cafes, airports), which of the following actions is MOST important for protecting your personal data?

✓ Correct Answer: Option D

A VPN encrypts your internet connection, creating a secure tunnel for your data, which is crucial when using insecure public Wi-Fi networks where malicious actors might intercept unencrypted data. Incognito mode only prevents your browser from saving history; it doesn't encrypt your connection. Limiting activity helps but isn't a primary security measure. A firewall is important but doesn't encrypt data in transit over an insecure network.