Final answer:
The presumption in the given scenario is that the tenant in the apartment house has the right to attach book cases to the wall.
Step-by-step explanation:
The presumption in the given scenario is that the tenant in the apartment house has the right to attach book cases to the wall.
This presumption is based on the principle of tenants having certain rights and responsibilities when it comes to making modifications to their rented property. However, it is important to note that the specific rights and responsibilities of tenants in regard to attaching fixtures may vary depending on the jurisdiction and the terms of the lease agreement.