Which of the following is required in a valid written lease

While having a witness signature can lend additional credibility and proof to the lease, it is not a legal requirement for a written lease to be valid in most jurisdictions. The essential components of a lease focus on the agreement between the landlord and tenant rather than the involvement of a witness.

Though a tenant security deposit is often a common practice in leasing, it is not mandatory for the validity of the lease itself. The lease can be legally binding without stipulating a security deposit, as the deposit is more about the financial arrangement than the lease's legality.

Including a provision regarding pets may be important for some landlords, but it is not a standard requirement for a lease to be valid. The lease can be enforceable without this clause, as it primarily concerns the rights and responsibilities related to tenancy rather than universally applicable terms.