Any trust institution that maintains a trust office in this state and its affected clients may designate as the state whose laws shall govern any written agreement between the trust institution and its client or any instrument under which the trust institution acts for a client and with respect to the fiduciary investment standards applicable to the agreements, either:
(1) This state;
(2) A state where affected clients reside; or
(3) The state where the trust institution has its principal office.