(a) A savings bank may, only after prior written approval of the Commissioner, invest in a subsidiary.(b) Subsequent to obtaining approval for its initial investment and activity, a subsidiary may not engage in additional or substitute activities without the prior written approval of the Commissioner.(c) A savings bank may, with prior written approval of the Commissioner, divest itself of a subsidiary or merge or consolidate the subsidiary with another company if the Commissioner finds that the terms and conditions of the transaction are in the best interests of the savings bank.