The correct answer is D) All the above. This is correct because: 1) It is imperative that the securing of cargo on flats and trailers and in containers be adequate for both road and sea motions, as the stresses and forces experienced at sea can be significantly different from road transport. 2) The movements experienced by road borne cargo, such as braking, acceleration, and cornering, differ significantly from the roll, pitch, and sway movements of a ship at sea, requiring different securing methods. 3) Adequate securing points on the vehicles themselves are necessary so that lashings can be properly and safely utilized to secure the cargo for sea transport. Therefore, all three statements are true and represent the key considerations for lashing requirements to secure vehicles aboard Ro-Ro vessels.