Android Debug Bridge (ADB) is a powerful debugging interface that, if misconfigured, allows attackers to execute commands remotely. CEH v13 identifies exposed ADB as a critical mobile security risk, especially in enterprise environments.
The most effective countermeasure is to disable ADB entirely, except when explicitly required for development or troubleshooting, and only within tightly controlled environments. This directly removes the attack vector.
VPNs and biometrics improve security but do not prevent ADB abuse. Updating MDM systems is important but does not eliminate the risk if ADB remains enabled.
CEH v13 explicitly recommends strict ADB control as a best practice. Therefore, Option C is the correct answer.