After you configure KPI thresholds, you can set up alerts to notify you when aggregate KPI severities change. ITSI generates notable events in Episode Review based on the alerting rules you configure.
Anomaly detection generates notable events when a KPI IT Service Intelligence (ITSI) deviates from an expected pattern.
Notable events are typically generated by a correlation search.
Reference:
https://docs.splunk.com/Documentation/ITSI/4.10.1/SI/AboutSI
A, B, and D are correct answers because ITSI can generate notable events when a KPI breaches a threshold, when a KPI detects an anomaly, or when a correlation search matches a defined pattern. These are the main ways that ITSI can alert you to potential issues or incidents in your IT environment. Reference: Configure KPI thresholds in ITSI, Apply anomaly detection to a KPI in ITSI, Generate events with correlation searches in ITSI