A legal arrangement created in a will or by a living person is known as what?

The concept described refers to a trust, which is a legal arrangement where one party holds property for the benefit of another. Trusts are commonly established through a will or created by a living individual, allowing for the management and distribution of assets according to specific instructions outlined by the person who created the trust. This arrangement can provide benefits such as avoiding probate, managing assets, and protecting the interests of beneficiaries.

In contrast, joint tenancy refers to a co-ownership structure typically involving the right of survivorship, which allows surviving owners to inherit the deceased owner's share automatically. Involuntary alienation involves the transfer of property without the owner's consent, usually through legal means such as foreclosure. The right of survivorship is a specific feature often associated with joint tenancies, signifying that upon the death of one tenant, the remaining co-owners automatically absorb the deceased’s share.

Ultimately, the correct answer is underpinned by the definition of a trust as a deliberate and structured method of asset management and distribution as expressed through a will or while living.