Final answer:
The Department of Labor is the regulatory agency that can relieve a fiduciary from a breach of fiduciary duty regarding Employee Benefit Plans, specifically through the Employee Benefits Security Administration.
Step-by-step explanation:
The regulatory agency empowered to relieve a fiduciary from a breach of fiduciary duty with regard to Employee Benefit Plans is the Department of Labor (DOL). The Department of Labor has the authority to enforce provisions of the Employee Retirement Income Security Act (ERISA), which sets minimum standards for most voluntarily established retirement and health plans in private industry to provide protection for individuals in these plans.
The DOL's Employee Benefits Security Administration (EBSA) is responsible for administering and enforcing the provisions of ERISA. The Internal Revenue Service (IRS) deals with the tax-related provisions of employee benefit plans, while the Federal Reserve and the Office of the Comptroller of the Currency supervise financial institutions and bank holding companies respectively, but not matters of fiduciary duty relief for employee benefit plans.