The correct answer is He slows the pace and startles the reader by having the watchman hesitate twice before firing.
The latter is undoubtly the most impactful technique the author could have used to surprise the reader. While getting to that point on the story might have done nothing but to confuse the reader - having no context to immerse the soldier in a dizzing state -, it is not until the reader reaches the end that the surprise factor kicks in, revealing the true identity of the horseman, and thus, providing an explanation for the climax.
The rest of the options are not as impactful since:
- Despite the author's detailed description of the scene setting, it does not contribute to the big surprise at the end of the story; the description merely serves as visual guidance to the reader throughout the story.
- It is expected that somebody who had recently joined an army and had not killed anyone yet, tends to draw conflict into the soldier's mind when presented with that opressive situation. Therefore, this setting does not cause much surprise.
- Transferring the reader's eyes from one character to another in a single scene is an interesting technique, but it is one that does not cause much surprise to the reader - unless they experience the perspective switching technique for the first time, in which case, the surprise should be slightly more significant, but not as much as the story's finale.
