Final answer:
Security deposits for commercial tenancy are defined by the lease agreements between the landlord and tenant, detailing the specific terms they have agreed upon.
Step-by-step explanation:
The amount and disposition of security deposits for commercial tenancy are primarily defined by C. Lease Agreements. While commercial law, real estate regulations, and tenancy acts provide a general legal framework, it is the lease agreement that outlines the specific terms agreed upon by the landlord and tenant regarding security deposits. It's essential for business owners to understand their rights and responsibilities, as detailed in the lease, and to comply with government regulations such as zoning.