Explanation
Encryption of network traffic is the most important control to mitigate the risk of potential personal data compromise when employees access corporate IT assets remotely. Encryption is a process that transforms data into an unreadable form, making it difficult for unauthorized parties to intercept, modify, or steal it.
Encryption of network traffic ensures that the data transmitted between the remote employees and the corporate network is protected from eavesdropping, tampering, or leakage.
Intrusion prevention system (IPS), firewall rules review, and intrusion detection system (IDS) are also useful controls for network security, but they are not as effective as encryption for protecting personal data in transit.
IPS and IDS can monitor and block malicious or suspicious network traffic, but they cannot prevent data exposure if the traffic is intercepted by a third party. Firewall rules review can help optimize and secure the firewall configuration, but it cannot guarantee that the firewall will not be bypassed or compromised by an attacker. Therefore, encryption of network traffic is the best option among the choices given.