Consider the below statements with respect to surveying and identify the correct answer.
Statement A: Latitude of a survey line is defined as its coordinate length measured in the
direction perpendicular to an assumed meridian direction.
Statement B: The type of levelling in which levels are taken on each side of a main line at right angles to that line in or- der to determine a vertical cross-section of the surface of the ground is called Differential levelling.

Correct option is D

Traverse computations:- The position of different points are plotted on a plan with reference to two lines which are respectively parallel and perpendicular to the meridian. Latitude:- The latitude of the line may therefore defined as the distance measured parallel to the meridian (north and south line).
Departure:- Departure defined as the distance measured parallel to the line perpendicular to the meridian (east and west line).

SL = Latitude is the projection on North-South meridian
D = Departure is the projection on East-West meridian
�� = Bearing angle
| = Length of the line.
L = l x cos ��
D = l x sin ��
Differential levelling:- Method of direct levelling the object of which is solely to find out the difference in elevation of two points regardless of the horizontal positions of the points with respect of each other, is known as differential levelling.