Answer: D. 105 Explanation: To determine which triangulation station is NOT visible from the edge of the quarry, we need to understand the concept of triangulation stations and visibility in geographical terms. Step 1: Understanding Triangulation Stations Triangulation stations are fixed points on the Earth's surface used in surveying and mapping. They are often marked by physical structures or markers and are used to create a network of triangles for accurate mapping. The visibility of these stations can be affected by various factors, including terrain, elevation, and obstructions. Step 2: Analyzing Visibility When considering visibility from the edge of a quarry, we must take into account the following: - Topography: The shape and features of the land can obstruct the line of sight. If a triangulation station is located behind a hill or a steep slope, it may not be visible from the quarry's edge. - Distance: The farther a triangulation station is from the edge of the quarry, the more likely it is to be obscured by terrain or other features. - Elevation: The height of the triangulation station relative to the edge of the quarry can also affect visibility. A station located at a higher elevation may be visible even from a distance, while one at a lower elevation may not be. Step 3: Evaluating Each Option - A. 82: This station may be positioned in a way that allows it to be visible from the edge of the quarry, possibly due to favorable topography or proximity. - B. 94: Similar to A, this station could be visible based on its location and the surrounding landscape. - C. 96: This station might also be visible, depending on its elevation and the absence of obstructions. - D. 105: This station is likely positioned in such a way that it is either too far away, at a lower elevation, or behind an obstruction (like a hill or the quarry wall), making it not visible from the edge of the quarry. Why Other Options Are Weaker:

• A, B, and C: These options are likely to be visible due to their proximity or favorable positioning. They may be located on higher ground or in open areas that do not have significant obstructions, making them more accessible for sighting from the quarry's edge.

Common Pitfalls:

• Assuming All Stations Are Visible: A common mistake is to assume that all triangulation stations can be seen from any point without considering the terrain and elevation.
• Ignoring Topography: Failing to analyze the landscape can lead to incorrect conclusions about visibility.
• Not Considering Distance: Overlooking the distance between the quarry edge and the triangulation stations can also result in errors.

Revision Summary:

• Triangulation stations are used for mapping and surveying and can be affected by terrain and elevation.
• Visibility from the edge of a quarry depends on topography, distance, and the elevation of the stations.
• Option D (105) is the correct answer as it is likely not visible due to obstructions or distance.
• Always analyze the landscape and consider all factors when determining visibility in geographical contexts.