The correct answer is: A. ranging
Ranging is the process of locating or identifying points lying on a contour. It is done by measuring the distance from a known point to the point to be located. The distance can be measured using a variety of methods, such as a tape measure, a range finder, or a laser range finder.
Centring is the process of determining the center of a point or object. It is done by measuring the distance from the point or object to two or more known points. The distance can be measured using a variety of methods, such as a tape measure, a range finder, or a laser range finder.
Horizontal control is the process of establishing a network of points on the ground whose elevations are known. This network is used to provide a reference for measuring the elevations of other points.
Vertical control is the process of establishing a network of points on the ground whose elevations are known. This network is used to provide a reference for measuring the elevations of other points.
In direct method of contouring, the process of locating or identifying points lying on a contour is called ranging. This is because the distance from a known point to the point to be located is measured. The distance can be measured using a variety of methods, such as a tape measure, a range finder, or a laser range finder.