(a) Except as provided in Subsection (b), a landlord who receives a security deposit or rent prepayment for a dwelling from a tenant who fails to occupy the dwelling according to a lease between the landlord and the tenant may not retain the security deposit or rent prepayment if:
(1) the tenant secures a replacement tenant satisfactory to the landlord and the replacement tenant occupies the dwelling on or before the commencement date of the lease; or
(2) the landlord secures a replacement tenant satisfactory to the landlord and the replacement tenant occupies the dwelling on or before the commencement date of the lease.
(b) If the landlord secures the replacement tenant, the landlord may retain and deduct from the security deposit or rent prepayment either:
(1) a sum agreed to in the lease as a lease cancellation fee; or
(2) actual expenses incurred by the landlord in securing the replacement, including a reasonable amount for the time of the landlord in securing the replacement tenant.