Which of the following is NOT one of the four unities required for joint tenancy?

In the context of joint tenancy, there are four unities that must be present for the joint tenancy to be valid. These unities are:

1. Possession: All joint tenants must have equal rights to possess and use the entire property.
2. Interest: All joint tenants must hold an equal share in the property. For instance, if there are two joint tenants, they each own 50% of the property.
3. Title: All joint tenants must hold their interest in the property under the same title, meaning they must acquire their interests simultaneously through the same legal document.
4. Time: All joint tenants must acquire their interests at the same time; they cannot have different start times for their ownership stakes.

The correct answer, identifying a concept that is not one of the four unities, is exclusivity. While exclusivity refers to a situation where ownership rights are held independently and separated from others, it is not a requirement for joint tenancy. Instead, joint tenancy emphasizes shared possession and interests among the tenants, which runs contrary to an exclusive ownership approach.