ANS:D - three point problem.

Locating the position of a plane table station with reference to three known points is known as the three-point problem. In the three-point problem, the position of the plane table station is determined by observing the angular relationships between the station and three known points whose positions are already established. By measuring the angles between the known points and the station using a theodolite or other surveying instruments, the exact location of the station can be calculated through trigonometric methods. The other methods mentioned have different applications in surveying:

• Intersection method: Involves locating a point by sighting and drawing lines from two or more known points to intersect at the desired location.
• Radiation method: Involves locating new points by measuring distances and directions from a single known point.
• Resection method: Involves locating the position of the observer (such as the plane table station) by observing angles to three or more known points.