Due professional care requires internal auditors to apply the care, skill, judgment, and diligence expected of a reasonably prudent and competent auditor. Considering technology-based audit techniques while also evaluating their cost relative to expected benefits demonstrates this balanced professional judgment. Repeating prior procedures without considering changes in risks or operations can result in inappropriate audit work. Investigating every discrepancy regardless of relevance is inefficient and inconsistent with risk-based auditing because audit effort should focus on matters that could affect organizational objectives. Avoiding expert assistance solely to reduce cost may also undermine audit quality when specialized knowledge is required. Internal Audit Fundamentals guidance specifically associates due professional care with considering the use of technology and data-analysis techniques when appropriate. Therefore, option C best demonstrates due professional care.