Comprehensive and Detailed Step-by-Step Explanation:
* Trend Analysis: This technique identifies patterns or shifts in performance by analyzing data over time. It is particularly effective for tracking metrics like revenue, expenses, or production volumes across reporting periods to spot anomalies or trends.

Comprehensive and Detailed Step-by-Step Explanation:
* Gathering Inputs for the Matrix: Interviews, walkthroughs, and questionnaires are primary tools for gathering detailed insights into risks, controls, and processes. These activities provide the information necessary to populate a risk and control matrix effectively.

Comprehensive and Detailed Step-by-Step Explanation:
* Reference to IIA Standards:
* Standard 1000 - Purpose, Authority, and Responsibility: The internal audit charter must define the purpose, authority, and responsibility of the internal audit activity and establish its position within the organization.
* The charter is foundational to the independence, authority, and effectiveness of the internal audit activity.
* Reasoning:
* Option A is correct because the charter formalizes the internal audit activity's role and ensures alignment with organizational governance. Without a charter, the internal audit function cannot operate effectively or independently.
* Option B (establishing a code of ethics) is important but is part of overall compliance with IIA Standard 1300 - Quality Assurance and Improvement Program and is not the first step.
* Option C (approving the budget) is administrative and secondary to establishing the internal audit charter.
* Importance of the Audit Charter:
* The charter provides the internal audit activity with the mandate to perform its duties, ensuring accountability and defining its scope and authority.