An internal auditor is starting the fieldwork of an assurance engagement.

Comprehensive and Detailed Explanation:

A walkthrough is an audit procedure in which the auditor follows a transaction through the entire process, discussing with control owners and observing how policies and procedures are applied. The primary purpose of this exercise is to assess the design of internal controls (C). It helps the auditor verify whether controls exist, are properly designed, and are implemented as described. Collecting policies (A) supports documentation, but policies alone do not confirm control design. Financial results (B) relate to performance reporting, not walkthroughs. Engagement objectives (D) are defined during planning, not during walkthrough. Therefore, the walkthrough’s goal is to evaluate whether controls are appropriately designed to mitigate risks, aligning with IIA Standard 2310 (sufficiency and relevance of information).