Final answer:
The most qualified individual for a concurring partner review is an experienced partner from the same firm who was not involved in the audit, ensuring independence and objectivity in the review process.
Step-by-step explanation:
An additional partner review, often called a concurring partner review, is an important quality control measure in the audit process. The most qualified individual to perform this review would be option c: An experienced partner of the firm who did not actively participate in the audit. This is because the concurring partner needs to be independent and objective, which is compromised for the engagement partner due to their involvement with the audit. An SEC employee is not a part of the audit firm and hence would not usually be involved in the firm's internal review process, while a partner from another firm, despite their understanding of the client, lacks the necessary current connection with the auditing firm's practices and policies to effectively serve in this quality control role.