According to ISO 50001.

When conducting internal audits of an Energy Management System (EnMS) in accordance with ISO 50001, auditors are expected to perform several key activities to ensure the system's effectiveness and continual improvement. These activities include:​

Focus on Areas of Significant Energy Use:Auditors should prioritize auditing areas that have substantial energy consumption, as improvements in these areas can lead to significant energy performance enhancements.

Review Written Procedures Related to the Area Under Audit:A thorough examination of documented procedures ensures that they align with ISO 50001 requirements and organizational practices. This review helps in identifying any discrepancies between documented procedures and actual practices.

Assess Actual Activities Against Written Procedures:Auditors compare on-ground activities with documented procedures to verify compliance and identify deviations. This assessment ensures that operations are performed as intended and in line with established protocols.

Look for Opportunities for Energy Improvement and Minimize Bureaucracy:Identifying opportunities for enhancing energy performance is a core objective of the audit.Auditors should also aim to streamline the EnMS by reducing unnecessary complexities, thereby making it more efficient and user-friendly.

By encompassing all these activities, internal auditors ensure a comprehensive evaluation of the EnMS, leading to effective energy management and continual improvement. Therefore, the correct answer is E. All of the above.