Ma and Pa Ferrell execute a deed that gives all the land known as Ferrell Funny Farm $"$to Shan, Nate, and Adam." The three are brothers, with Shan being the oldest, followed by Nate, followed by Adam. Knowing this, and only this, what do Shan, Nate, and Adam have?

Shan gets an initial life estate, and when he passes, the property goes to Nate, and when Nate dies, fee simple absolute vests in Adam.

Each of them has a $\frac{1}{3}$ divided interest as joint tenants with right of survivorship.

Shan, the oldest, gets a $\frac{1}{2}$ undivided tenancy in common interest $($per Oklahoma law for firstborn children$)$ and Nate and Adam each get $\frac{1}{4}$ interests as joint tenants with right of survivorship.

Each of them has a $\frac{1}{3}$ undivided interest as tenants in common.