(a) By a signed writing, a party may designate one or more persons other than a party as his or her agent on an account. Unless the terms of the agency designation provide otherwise, the agency designation may be revoked or amended only by the party making the designation or by a guardian, conservator, or other fiduciary appointed by a court of the party's domicile and charged with the management of the account.
(b) Unless the terms of an agency designation provide otherwise, the agent's authority survives disability, incompetency, and incapacity of the party making the agency designation. The agent may act for a disabled, incompetent, or incapacitated party until the authority of the agent is revoked.
(c) Death of the party making the agency designation terminates the authority of an agent.