To achieve visibility into SaaS usage across users, which of the following is the BEST solution to implement so consumers can monitor their own users?

An Intrusion Detection System (IDS) is designed to detect malicious activities and policy violations within a network, not to provide general visibility into legitimate SaaS usage patterns across users.

A Cloud Access Security Broker (CASB) primarily focuses on security, compliance, and governance for cloud services, providing visibility into cloud usage from a security policy enforcement and data protection perspective, rather than granular operational usage and performance metrics for consumers.

Multi-Factor Authentication (MFA) is an identity verification method used to enhance security during login and does not provide visibility into SaaS usage after authentication.

Application Performance Monitoring (APM) provides detailed visibility into the operational aspects of SaaS usage, including user activity, transaction tracing, response times, and resource consumption within the application. This allows consumers to understand how their users are interacting with the SaaS application, identify performance bottlenecks, and monitor overall user experience.