A trust account best meets the mother’s objective because a trust can be structured to control distributions and restrict the beneficiary’s access to funds. By establishing a trust, the mother (as grantor) can define terms such as when the son may receive distributions, what the funds may be used for (e.g., education only), and who has the authority to approve withdrawals (the trustee). This directly addresses the stated goal: making annual gifts while preventing the son from withdrawing funds for living expenses. Therefore, A is correct.

A separately managed account (choice B) is an investment management arrangement, not a legal structure designed to restrict a beneficiary’s access. It focuses on portfolio management and customization, but it does not inherently prevent the account owner (or someone with authority) from accessing funds, and it does not solve the “no withdrawals for living expenses” objective the way a trust can.

A Coverdell ESA (choice C) is intended for education expenses and has tax-advantaged features, but it is not the best answer because the mother’s objective is broader: she wants to make yearly gifts and restrict withdrawals generally (especially for living expenses). While a Coverdell can constrain qualified use and impose penalties for nonqualified withdrawals, it is still an education account with specific rules and limits rather than a flexible legal mechanism to restrict access across circumstances. A JTWROS account (choice D) is especially wrong for this objective because a joint owner typically has immediate rights to the assets, meaning the son could withdraw funds.

SIE-wise, this is an account registration/control question: trusts are the primary tool for controlling who can access assets and under what terms, making them ideal when the goal is to give assets but restrict the beneficiary’s spending access.