Final answer:
The set of words from the selection that reflects its theme is 'hostile, danger-sign, attacked,' as they capture the essence of the conflict and turmoil of war depicted in the passages.
Step-by-step explanation:
The set of words from the selection that reflects its theme can be determined by looking at the overarching ideas presented in the excerpts provided. From the examples given, we can infer that war and the transformation of one's perception about it are central themes. Words like bravery, splendor, and hostile resonate with this theme, demonstrating how war is often idealized but in reality, is harsh and brutal. Thus, the phrase hostile, danger-sign, attacked seems to reflect the theme of the selection most accurately, considering that it encompasses the essence of the conflict and turmoil of war described in the passages. Furthermore, the transformation in vocabulary from glorified terms like adventure and memorable feats of discovery and conquest to the grim reality of war (e.g., thunder of the captains and the shouting and monstrous shadows) alludes to a shift from romanticized views to the harshness of warfare.