The correct answer is D) drilling a hole at each end of the crack. Drilling a hole at each end of a crack in the deck plating of a vessel is the correct temporary measure to prevent the crack from increasing in length. This technique works by stopping the propagation of the crack, as the holes create a stress relief point that prevents the crack from spreading further. This is a commonly accepted temporary repair method until more permanent welding or plating can be done. The other options are not the best temporary fixes. Slot-welding the crack (A) or welding a doubler over it (B) may stop the immediate growth, but could potentially lead to further cracking. Cutting a square notch at each end (C) is less effective than drilling holes for stress relief.