A commission in the national guard may be vacated:
1. At any time when it is determined by an efficiency board as provided by federal regulation that the officer holding the commission is no longer fit for service by reason of the officer's moral character, capacity, or general fitness for service;2. By resignation of the officer holding the commission;3. By the absence of the officer without leave for a period of three months; or4. Pursuant to the sentence of a court-martial. Officers of the national guard who are rendered superfluous by the disbandment of their organization must be disposed of as provided by federal law. An officer, upon application therefor, may be placed in the reserve in such manner as may be authorized by federal law.