The correct answer is: A. method of perpendicular offsets.
The method of perpendicular offsets is a surveying technique used to determine the horizontal and vertical distances from a known point to an unknown point. The method involves measuring the distances from the known point to a series of points that are perpendicular to the line of sight between the known point and the unknown point. The horizontal and vertical distances to the unknown point can then be calculated using these measurements.
The method of oblique offsets is a surveying technique that is similar to the method of perpendicular offsets, but the offsets are not perpendicular to the line of sight between the known point and the unknown point. This makes the method of oblique offsets less accurate than the method of perpendicular offsets.
The method of ties is a surveying technique that is used to connect two or more points that are not in line with each other. The method involves measuring the distances between the points and then using these measurements to calculate the angles between the lines connecting the points.
All of the methods of offsets involve measuring distances on the ground. However, the method of perpendicular offsets involves measuring the shortest distances between the known point and the unknown point, which makes it the most accurate method.