What type of trust takes effect at the trustor's death?

A testamentary trust is a specialized type of trust that is established according to the instructions laid out in a person's will and only takes effect after the individual’s death. This trust is funded by the assets of the estate upon the death of the testator, the person who has made the will.

The key feature of a testamentary trust is its reliance on the will to come into existence, differentiating it from other types of trusts which can be created during a person's lifetime. For example, an inter vivos trust is set up and funded while the trustor is still alive, thus functioning during their lifetime. On the other hand, constructive and resulting trusts are legal constructs that arise under specific conditions, often to resolve disputes or to manage property that involves equitable interests, rather than being established through a will.

Therefore, the testamentary trust is distinctive for its timing and the legal framework that enables it to operate, making it the correct choice for a trust that takes effect upon the trustor's death.