In the cross-section method of indirect contouring, the spacing of cross-sections depends upon i) contour interval ii) scale of plan iii) characteristics of ground The correct answer is A. only (i) B. (i) and (ii) C. (ii) and (iii) D. (i), (ii) and (iii)

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 the spacing of cross-sections. For example, more cross-sections will be required to accurately represent a hilly area than a flat area.

In conclusion, the spacing of cross-sections in the cross-section method of indirect contouring depends on the contour interval, the scale of plan, and the characteristics of ground.