(a)Except as provided in subsection (b), an amount withdrawn from an account under this chapter shall be treated as withdrawn on a first-in-first-out basis.
(b)An amount withdrawn from an account under this chapter shall be treated as withdrawn on a last-in-first-out basis if it is—
(1)a nonqualified withdrawal for research, development, and design expenses incident to new and advanced vessel design, machinery, and equipment; or
(2)an amount treated as a nonqualified withdrawal under section 53510(d) of this title.