What are common sources of improvement opportunities for the ISMS?

• A.Customer complaints, marketing surveys, competitor product launches, industry conference talks, vendor roadmaps, social-media sentiment, and the annual staff engagement survey
• B.Internal audits, management reviews, incident analysis, risk assessments, monitoring results, feedback from interested parties, and technology changes
• C.Security incidents alone, analysed through the incident register, the SIEM alert history, the help-desk ticket queue, the vulnerability scanner output, and the threat-intelligence feed
• D.Certification audit findings, the surveillance audit report, and the certification body's opportunities for improvement