Which of the following is an item that should be included in an incident report...

A high-quality incident report captures what the adversary did in a way that enables prevention and detection improvements. Including adversary tactics and techniques (C) is essential because it translates raw artifacts (emails, URLs, headers, click events) into actionable security engineering outcomes: which initial access method was used (credential phishing vs BEC), which impersonation technique (display name, lookalike domain, supplier compromise), what persistence was attempted (mailbox rules/forwarding, OAuth consent), and what objectives were pursued (invoice fraud, data theft, lateral phishing). In Proofpoint-centered IR, mapping tactics and techniques supports targeted control tuning: URL Defense policy, attachment sandboxing, impostor rules, DMARC enforcement, and TRAP automation; it also improves analyst playbooks (what pivots to run next time, what indicators to hunt). The incident response plan (B) is a reference document, not an incident-specific report item. Network diagrams (A) may be helpful in some incidents but are not always relevant for email-led events. Threat landscape reporting (D) is contextual intel, but the report must focus on what occurred in this incident and what to change to reduce recurrence, which is best captured via tactics/techniques.