Social engineering is the practice of manipulating people into performing actions or divulging confidential information, often by impersonating someone else or creating a sense of urgency or trust. The suspicious caller in this scenario was trying to use social engineering to trick the user into giving away credit card information by pretending to be the CFO and asking for a payment. The user recognized this as a potential scam and reported it to the IT help desk. The other topics are not relevant to this situation. References: CompTIA Security+ Study Guide: Exam SY0-701, 9th Edition, page 19 1

A honeytoken is a form of deception technology in which a fake asset (such as credentials, files, or database records) is planted in a system or network to detect unauthorized access or malicious activity. The fake password stored in a hidden spreadsheet, with monitoring for access, is a classic example of a honeytoken. It is not an interactive system (like a honeypot or honeynet) but rather a marker or tripwire intended to alert the security team to suspicious behavior. This method helps identify attackers and their methods early in the intrusion process.
References:
CompTIA Security+ SY0-701 Official Study Guide, Domain 1.1, "Deception and Disruption Technologies" CompTIA Security+ Exam Objectives: 1.1 CompTIA Glossary: "Honeytoken-A fictitious record or file intended to attract or identify unauthorized access."

Root cause analysis is a process of identifying and resolving the underlying factors that led to an incident. By conducting root cause analysis as part of incident response, security professionals can learn from the incident and implement corrective actions to prevent future incidents of the same nature. For example, if the root cause of a data breach was a weak password policy, the security team can enforce a stronger password policy and educate users on the importance of password security. Root cause analysis can also help to improve security processes, policies, and procedures, and to enhance security awareness and culture within the organization.
Root cause analysis is not meant to gather loCs (indicators of compromise) for the investigation, as this is a task performed during the identification and analysis phases of incident response. Root cause analysis is also not meant to discover which systems have been affected or to eradicate any trace of malware on the network, as these are tasks performed during the containment and eradication phases of incident response. References = CompTIA Security+ SY0-701 Certification Study Guide, page 424-425; Professor Messer's CompTIA SY0-701 Security+ Training Course, video 5.1 - Incident Response, 9:55 - 11:18.