Explanation
When identifying which servers are no longer required, reviewing server CPU usage trends is the most helpful approach. Monitoring the CPU usage over time provides insights into how actively a server is being utilized.
Servers with consistently low CPU usage may be candidates for consolidation or decommissioning. By analyzing CPU utilization patterns, IT management can make informed decisions about which servers can be retired without impacting performance or availability1.
References:
ISACA. "Technical Guide on IT Migration Audit." 1
(http://kb.icai.org/pdfs/PDFFile5b278a12a66758.27269499.pdf)
Zapier. "IT audit: The ultimate guide [with checklist]." 2(https://zapier.com/blog/it-audit/) ISACA. "CISA Certification | Certified Information Systems Auditor." 3(https://www.isaca.org/credentialing/cisa)

The systems inventory containing personal data is a crucial element for auditing an organization's data privacy practices. The systems inventory is a list of all the systems, applications, databases, and devices that collect, store, process, or transmit personal data within the organization12. The systems inventory helps the auditor to identify the scope, location, ownership, and classification of personal data, as well as the risks and controls associated with them12. The systems inventory also helps the auditor to verify compliance with data privacy laws, regulations, and internal policies that apply to different types of personal data

Section: Protection of Information Assets