(a) Promotions to the ranks of sergeant and lieutenant shall be based upon the results of a written examination and an oral interview. Promotions to the rank of captain, major, lieutenant colonel, or colonel shall be made by the Commissioner and it shall not be required that such promotions be based on written and oral examinations.
(b) Nondisciplinary transfers shall be grievable directly to the Vermont Labor Relations Board in accordance with the rules of practice of the Board. In any such grievance, the burden shall be on the grievant to establish that the transfer was either discriminatory or disciplinary.