The correct answer is D. (i), (ii) and (iii).
The spacing of cross-sections in the cross-section method of indirect contouring depends on the following factors:
- Contour interval: The contour interval is the vertical distance between two consecutive contour lines. The closer the contour lines, the steeper the slope. A smaller contour interval will require more cross-sections to be taken in order to accurately represent the ground surface.
- Scale of plan: The scale of the plan is the ratio of the distance on the map to the actual distance on the ground. A larger scale will require more cross-sections to be taken in order to accurately represent the ground surface.
- Characteristics of ground: The characteristics of the ground, such as the presence of hills, valleys, and other features, will also affect 75.5c-23.5 6.3-42 24.9-48.3 48.6-11.4 42.9-11.4 132.3-11.4 132.3s0 89.4 11.4 132.3c6.3 23.7 24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.2 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z"/> Subscribe on YouTube