Final answer:
The statement is false; the correct term that includes vested and nonvested service using future salary levels is the projected benefit obligation, not the accumulated benefit obligation.
Step-by-step explanation:
The statement "The accumulated benefit obligation bases the deferred compensation amount on both vested and nonvested service using future salary levels" is false.
The concept described here is actually the projected benefit obligation (PBO), not the accumulated benefit obligation. While the PBO does consider future salary levels in addition to vested and nonvested service, the accumulated benefit obligation (ABO) measures the pension liability on the assumption that the company will freeze the benefits earned by employees up to the calculation date and does not account for future salary increases.