B, based off the fact they called them loyal, but not 100% sure.
The plot of "The Signalman" reaches a climax when signalman dies. As you know, the main characteristic of climax is that it is the most emotional part of a story that provides a lot of interest and suspense to a reader. The death of signalman is the highest point of emotional intensity of the plot as the loved protagonist unexpectedly (or undesirably) passes away and put an end to the story.
