The correct answer is B) decrease due to the increase in steam volume used. When a single furnace boiler receives a full astern bell from half ahead, the steam demand from the engine will increase significantly. This will result in a higher volume of steam being drawn from the boiler. To meet this increased demand, the boiler will need to increase its firing rate, but the superheater outlet temperature will actually decrease momentarily due to the larger volume of steam passing through the superheater. The other options are incorrect because: A) the temperature would not remain the same due to the increased steam demand, C) the temperature would not increase sharply as the boiler is simply meeting the increased load demand, and D) the temperature would not decrease and then increase, it would just decrease due to the higher steam volume.