正解:C
The first step for the security incident response team after an IS security attack is reported is to perform a damage assessment. This involves identifying the scope, impact and root cause of the incident, as well as collecting and preserving evidence for further analysis and investigation. Reporting results to management, documenting lessons learned and prioritizing resources for corrective action are important steps, but they should be done after the damage assessment is completed. References: CISA Review Manual (DigitalVersion), Chapter 6, Section 6.31