In its final decision on the proposed action or, if appropriate, in its recommendation to Congress, the Commission shall consider all the alternatives in the environmental impact statement and other relevant environmental documents and shall prepare a concise statement which, in accordance with CEQ Regulation § 1505.2, shall:
(a) Identify all alternatives considered by the Commission in reaching its decision or recommendation, specifying the alternatives which were considered to be environmentally preferable;
(b) State whether all practicable means to avoid or minimize environmental harm from the alternative selected have been adopted, and if not, why they were not.