Property held by lessee
In the case of a lessee, in determining the depreciation adjustments which would have resulted in respect of any building erected (or other improvement made) on the leased property, or in respect of any cost of acquiring the lease, the lease period shall be treated as including all renewal periods. For purposes of the preceding sentence—
(A)#
the term “renewal period” means any period for which the lease may be renewed, extended, or continued pursuant to an option exercisable by the lessee, but
(B)#
the inclusion of renewal periods shall not extend the period taken into account by more than ⅔ of the period on the basis of which the depreciation adjustments were allowed.