What additional data must be defined when using Secure Connect for an account not in the Vault?

In the context of using Secure Connect in CyberArk for accounts that are not stored in the Vault, defining subnet address ranges is crucial. The reason for this is that Secure Connect establishes secure and direct connections between resources, which requires an understanding of the network environment to ensure that the connections are valid and authorized. By specifying subnet address ranges, you define the IP ranges that are permitted to access the resources securely. This helps in managing and restrictively controlling access, enhancing the security model by not allowing unrestricted connections from any source.

Other options might involve aspects of security and permissions in a broad sense, but subnet address ranges are specifically tied to the necessity of defining where connections can be established from, which is uniquely aligned with the Secure Connect feature when handling accounts that aren't managed within the CyberArk Vault.