In which form of ownership does a spouse inherit the other spouse's interest upon death?

In the context of real estate ownership, the correct answer is tenancy by the entirety. This form of ownership is specifically designed for married couples, where both spouses hold equal ownership of the property. Upon the death of one spouse, the surviving spouse automatically inherits the deceased spouse's interest in the property. This feature is known as the right of survivorship, which ensures that ownership remains intact within the marital partnership and avoids the need for probate proceedings.

Other forms of ownership, while they may include elements of survivorship or joint ownership, do not specifically apply to married couples in the same way. For instance, in community property states, property acquired during the marriage is owned equally by both spouses, but upon death, the deceased spouse's share may not transfer automatically to the surviving spouse without proper estate planning. Tenancy in common allows for ownership by multiple parties where each person's share can be willed to someone else, which wouldn't guarantee automatic inheritance between spouses. Therefore, tenancy by the entirety is distinctly set apart due to its automatic transfer and the fact that only married couples can hold property in this manner.