When faced with numerous alerts in the Targeted Attack Protection (TAP) dashboard, the most effective first step is to triage and prioritize. The TAP Threats page provides powerful filtering and sorting capabilities, allowing an analyst to organize alerts by threat severity (e.g., active malware, phishing), threat type, delivery status (e.g., delivered, blocked), or timeframe. Applying these filters helps the analyst to quickly isolate the most critical threats that require immediate attention, establishing an efficient workflow before diving into the forensic details of any single alert.

B: Assessing false positives is a part of the investigation process for a specific alert, which occurs after initial prioritization, not before.

C: Opening and examining an email's .eml file is a deep-dive forensic step performed on a high-priority alert, not the first action when reviewing the entire queue.

D: Investigating false negatives (missed threats) is a separate workflow, typically initiated by a user report, and is not part of reviewing existing TAP alerts.

1. Proofpoint, Inc. (2023). Targeted Attack Protection (TAP) Administrator Guide. "Threats Dashboard" and "Filtering Threats" sections. The documentation outlines the user interface and explicitly details the use of filters as the primary method for managing and prioritizing threat alerts.

2. Proofpoint Learning. (2023). PPAN01: Proofpoint Accredited Security Analyst. Module: "Investigating Threats with TAP". This official courseware instructs analysts to begin their review process by using the filtering options on the TAP dashboard to manage the alert queue effectively.