The defining characteristic of a joint tenancy is the right of survivorship. This means that when one joint tenant passes away, their interest in the property automatically transfers to the surviving joint tenants, rather than being passed on according to a will or through inheritance laws. This feature creates a unique form of co-ownership where the remaining owners maintain their share without the need for probate, ensuring a seamless transition of ownership among the joint tenants.
In contrast, the other options do not pertain to joint tenancy in the same way. For instance, being able to will ownership to heirs is typical of tenancy in common, not joint tenancy, where the right of survivorship prevails. The idea that interests pass directly to heirs applies to forms of ownership like tenancy in common, which lacks survivorship rights. As for selling interests, while tenants in common can freely sell their shares, joint tenants generally cannot do so without severing the joint tenancy arrangement, thus losing the right of survivorship. Each characteristic reinforces why the right of survivorship is central to the definition of joint tenancy.