An estate where each tenant holds an undivided interest and unity of possession describes which ownership type?

The correct choice describes "tenancy in common," which is characterized by each tenant holding an undivided interest in the property. This means that multiple owners all share the same rights to the entire property, rather than dividing it into separate portions. Each owner's share can be unequal, and there is no right of survivorship as there is in joint tenancy; the ownership can be inherited or transferred independently.

Unity of possession is a key aspect of this ownership type, indicating that all tenants have the right to possess and use the entire property regardless of the percentage of ownership they hold. This legal structure promotes flexibility in ownership since each tenant can sell or bequeath their share without affecting the other co-owners.

In contrast, joint tenancy includes the right of survivorship, meaning that if one tenant passes away, their interest automatically transfers to the surviving tenants. Ownership in severalty refers to property held by one individual, while co-ownership is a broader category that encompasses different forms of multiple ownership, including both tenancy in common and joint tenancy. However, "tenancy in common" specifically captures the essence of undivided interest and unity of possession, making it the most precise definition in this context.