(a) The board of trustees of any school district within the state may deny admission to any child who:
(i) Has completed the twelfth grade; or (ii) Has such a mental or physical disability that based upon a physician's certificate the board believes such child could not reasonably benefit from the programs available or the attendance of such child would be inimical to the health, safety, or welfare of other pupils; provided, that the board shall make the best possible provision for suitable and adequate education of such child in accordance with the laws of this state.