Payment of benefits on account of minors, disabled persons and others. Benefits under this Article due minors or disabled persons as defined in Section 16-140(4) may be paid (1) to any person who has legally qualified and is acting as guardian of the minor’s or disabled person’s person or property in any jurisdiction; or (2) to a parent of the minor or to any adult person with whom the minor or disabled person may be residing, provided the board is assured that the moneys will be held in trust or used for the support of the minor or disabled person; or (3) to the trustee of a trust established for the benefit of the minor or disabled person. In addition, an adult person to whom benefits under this Article may be paid, while of sound mind and memory, may designate in writing any adult person with whom he or she resides or who provides responsible assistance or advice to him or her in the conduct of his or her affairs to receive benefits due or to become due to him or her under this Article, and benefits may be paid in accordance with such designation provided the board is assured that the same will be held in trust or used for the support of the person making such designation. The written receipt from the parent or other adult person shall constitute an absolute discharge of the system’s liability in respect of the amounts paid by the system.