What type of property interest is characterized by perpetual ownership under certain conditions, with reversion if violated?

The correct answer emphasizes the concept of a fee simple defeasible, which represents a type of property ownership that comes with specific conditions. This type of interest allows the owner to possess the property indefinitely; however, it can be forfeited or reverted back to the original grantor if certain stipulated conditions are not met or violated. This creates a unique dynamic in property law whereby the owner's rights are subject to these limitations.

For example, if the property is designated for a specific use – such as being used as a park – and the owner changes that use, the property can revert to the original owner or their heirs.

In contrast, a life estate grants ownership for the duration of a person's life, after which the property reverts to another party, but it does not involve conditions attached to ownership beyond duration. A fee simple absolute represents complete ownership with no conditions, allowing the owner full rights to the property without the risk of reversion due to violation of conditions. Joint tenancy involves co-ownership with rights of survivorship, which does not apply to the concept of conditions concerning ownership and reversion tied to the property itself. Thus, fee simple defeasible is the only option that aligns accurately with the description provided.