The only internal auditor, who was part of a larger team of individuals trained in...

Comprehensive and Detailed Explanation:

Per Standard 1210 – Proficiency, internal auditors must possess the necessary knowledge, skills, and competencies to perform engagements. If expertise is lacking internally, the CAE can obtain it through training, consulting, or external resources. In this case, the best solution is to engage another trained employee from within the organization (C) who has the required technical expertise in quality control equipment.

Canceling or postponing the audit (A) undermines risk-based planning.

Removing testing (B) weakens assurance and fails to meet objectives.

Outsourcing to external auditors (D) may be possible but is less efficient than leveraging internal expertise already available.

Thus, Option C aligns best with IIA standards, ensuring proper expertise while maintaining the audit’s integrity.