(1) The board of trustees may convene in executive session whenever it is deemed necessary to discuss any matters affecting national security, the selection of a site or the acquisition of real estate by lease or purchase when publicity regarding such consideration would cause a likelihood of increased price; the appointment, employment, or dismissal of an employee; or to hear complaints or charges brought against such employee by a public officer, person, or employee, unless such employee requests a public hearing. The governing body may exclude from such executive session during the examination of a witness on any such matter, any or all other witnesses in the matter being investigated by the governing body.

(2) No official business of the board of trustees shall be acted upon in executive session.