What does alerting on response time degradations and error rate increases start after?

The correct choice indicates that alerting on response time degradations and error rate increases begins once the baseline cube is ready. The baseline cube is a critical component in Dynatrace's monitoring framework as it provides a point of reference for normal performance metrics over time. Establishing this baseline allows Dynatrace to differentiate between typical performance levels and potential anomalies.

Once the baseline is established, the system has enough historical data to identify deviations that signify performance issues. This helps in accurately triggering alerts when there are significant changes in response times or error rates, enabling proactive management of application performance.

When other options are considered, they lack the context needed to establish a reliable monitoring framework. For example, relying on a fixed monitoring period or specific traffic patterns may not capture the dynamic nature of application usage or performance adequately. The emphasis on a baseline ensures that alerts are more precise and relevant, which is essential for effective application performance management.