Who is responsible for the overall administration and operation of a retirement plan according to ERISA?

The correct choice relating to the responsibility for the overall administration and operation of a retirement plan according to ERISA is the ERISA 3(16) Plan Administrator. This role is defined under the Employee Retirement Income Security Act (ERISA), which outlines the duties and responsibilities of those managing retirement plans.

The ERISA 3(16) Plan Administrator is tasked with ensuring that the plan is operated in compliance with all federal regulations and the plan documents. This includes responsibilities such as filing necessary forms with the government, overseeing plan operations, and handling participant communications related to plan benefits. This individual or entity takes on a fiduciary responsibility for the plan, making them critically important to lawful and effective plan administration.

In contrast, while the plan sponsor may initially create and maintain the plan, they do not automatically assume the active administrative responsibilities unless they also take on the role of the Plan Administrator. Similarly, a qualified plan fiduciary has specific fiduciary duties related to the plan but may not manage day-to-day operations. Lastly, the plan trustee holds and manages plan assets but doesn't handle the overall administrative operations as defined under ERISA. Each of these roles is essential to the functioning of retirement plans, but the Plan Administrator is specifically responsible for the plan’s overall administration