The narrative technique that is most commonly used by writers to describe setting is foreshadowing. However, it should be noted that while foreshadowing can help set a mood or hint at future events within a story, it's not primarily focused on describing the setting itself.
The other options—plot, dialogue, and pacing—also have distinct roles in storytelling. Dialogue can reveal elements of the setting through characters' interactions and conversations, while pacing refers to the speed at which a story unfolds, which can influence how much detail about the setting is given. Plot is the sequence of events in the story, but it doesn't specifically relate to setting description.
Thus, while dialogue can be a direct way to describe the setting through character interactions, if you're looking for a single narrative technique focused on setting description, it would typically be done through evocative language and imagery rather than being categorized under the listed options.