The board of directors, if they deem it not for the best interest of the district to grant such domestic annexation, shall order that the petition be rejected. But if they deem it for the best interest of the district, and if no person interested shall show cause why such domestic annexation should not be granted, or if having shown cause, withdraws the same, the board may order, without any election, that domestic annexation be granted as to the lands mentioned in the petition, or some part thereof. The order shall describe the lands to which domestic annexation shall be granted, and the board may cause a survey thereof to be made if deemed necessary.