You want to migrate to a Google Cloud-based solution for checking and (Digital Leader)

Correct answer: B) Identity Platform.
For checking and maintaining user identities, as well as controlling access to different resources based on their identity, you should choose a dedicated identity management solution. Google Cloud Identity Platform is designed for this purpose. It provides a secure and scalable authentication and identity management service that integrates with various authentication methods, including social identity providers and multi-factor authentication.
Options A (VPN tunnels), C (Compute Engine firewall rules), and D (Private Google Access) are not specifically designed for user authentication and identity management. VPN tunnels are used for secure network connections, Compute Engine firewall rules are for controlling traffic to VM instances, and Private Google Access is for accessing Google Cloud services without public IP addresses. They do not address the specific requirements of managing user identities for mobile apps and websites.