Choice "a" is correct. If a revocable trust is created by a grantor, the trust assets may be returned to the grantor upon the grantor's "revocation" of the trust (i.e., no "complete" gift exists); thus, the assets never left the control (or possible ownership) of the grantor and remain includible in the gross estate of the grantor.

Choice "b" is incorrect. When a trust is established for a minor, a complete gift is made to the trust, and the assets are no longer includible in the estate of the grantor.

Choice "c" is incorrect. The trustee typically has the power to distribute trust income in various types of trusts; thus, this fact alone would not make the assets includible in the gross estate of the grantor.

Choice "d" is incorrect. This type of arrangement has nothing to do with the requirement of assets to be included in the gross estate of the grantor, as it could exist in an irrevocable trust or a revocable trust. The beneficiary is simply passing his/her distribution to another party.