What type of ownership involves overlapping interests in a property complex such as condominiums and timeshares?

Common interest ownership is the correct answer because it encompasses ownership structures where multiple parties share ownership rights in a property complex, such as condominiums and timeshares. In these arrangements, individuals own their specific unit while also having shared interests in common areas and amenities, like swimming pools, hallways, and gardens. This type of ownership structure allows for diverse use and interests within shared properties, requiring rules and regulations to manage the use and maintenance of common spaces effectively.

The other ownership types mentioned do not involve overlapping interests in the same way. Joint tenancy ownership primarily pertains to a legal arrangement where two or more individuals hold title to a property together with rights of survivorship, which does not inherently involve shared interests in common areas in a larger complex. Freehold estate ownership and fee simple ownership refer to forms of land ownership where an individual has complete control and ownership rights over a property, typically without the complex shared interests found in condominium or timeshare structures.