Users must be able to connect remotely from their own mobile devices. What should the architect consider to increase the security of the current authentication solution?

Adding a second authentication factor, also known as multi-factor authentication (MFA), significantly increases security by requiring users to provide two or more verification factors to gain access, making it much harder for unauthorized users to compromise an account even if they know the password. This is particularly crucial for remote access from personal mobile devices where device security might be less controlled.

Placing domain controllers in the DMZ exposes critical infrastructure components to external threats and significantly increases the attack surface, which is a severe security risk rather than an improvement.

Shortening the Active Directory password expiration period can improve security by forcing more frequent password changes but often leads to user fatigue and weak, predictable passwords, and it does not inherently protect against real-time credential theft like MFA.

Populating the RDS user profile path in Active Directory user accounts is related to Remote Desktop Services configuration for user profiles, not a direct measure to increase the security of the authentication process itself for remote mobile access.