One-participant retirement plan .—
For purposes of clause (iii), the term “one-participant retirement plan” means a retirement plan that on the first day of the plan year—
(I)#
covered only one individual (or the individual and the individual’s spouse) and the individual (or the individual and the individual’s spouse) owned 100 percent of the plan sponsor (whether or not incorporated), or
(II)#
covered only one or more partners (or partners and their spouses) in the plan sponsor.