Lease term means the period during which the lessee has use of the property subject to the rental agreement, including any option of the lessor to renew or extend the term of the agreement. An option of the lessee to renew or extend the term of the agreement is included in the lease term only if it is expected, as of the agreement date, that the option will be exercised. For this purpose, a lessee is generally expected to exercise an option if, for example, as of the agreement date the rent for the option period is less than the expected fair market value rental for such period. The lessor's or lessee's determination that an option period is either included in or excluded from the lease term is not binding on the Commissioner. If the lessee (or a related person) agrees that one or both of them will or could be obligated to make payments in the nature of rent (within the meaning of 1.168(i)-2(b)(2)) for a period when another lessee (the substitute lessee) or the lessor will have use of the property subject to the rental agreement, the Commissioner may, in appropriate cases, treat the period when the substitute lessee or lessor will have use of the property as part of the lease term. See 1.467-7(f) for special rules applicable to the lessee, substitute lessee, and lessor. This paragraph (h)(6) applies to section 467 rental agreements entered into after March 6, 2001. However, taxpayers may choose to apply this paragraph (h)(6) to any rental agreement that is described in 1.467-9(a) and is entered into on or before March 6, 2001.