The board shall annually elect the officers of the state trust company, who serve at the pleasure of the board. The state trust company must have a principal executive officer primarily responsible for the execution of board policies and operation of the state trust company and an officer responsible for the maintenance and storage of all corporate books and records of the state trust company and for required attestation of signatures. The board may appoint other officers of the state trust company as the board considers necessary. The duties of any two or more officers may be combined by the board and held by one person.