In event correlation (as applied in SOC/SIEM-driven investigations), the workflow typically starts byreducing complexityandnormalizing what “one incident” looks likebefore attempting conclusions about causality.Event aggregation (2)is performed early to combine multiple low-level, related events (for example repeated authentication failures, repeated firewall denies, or multiple IDS hits for the same signature) into higher-level “grouped” records. This prevents analysts from treating every raw log line as a separate incident and makes correlation computationally and operationally feasible.

Next,event masking (1)suppresses events that are already known to be irrelevant or repetitive in a way that does not add investigative value (for example, routine scheduled scans, approved admin tools, or duplicate alerts already represented in the aggregated set). After masking,event filtering (4)further removes remaining noise using rules, thresholds, whitelists, time windows, or relevance criteria (scope, asset criticality, and known-benign sources), leaving a cleaner dataset that represents probable security-relevant activity.

Only after the dataset is consolidated and noise-reduced doesroot cause analysis (3)become reliable, because RCA depends on a clear chain of correlated events to identify the initiating action and propagation path. Hence the correct sequence is2 → 1 → 4 → 3 (Option B).