The most commonly used method of topographical survey used on a large area -

Correct option is B

· Theodolite and Stadia Method:
· This method is the most commonly used for topographical surveys on large areas.
· It involves using a theodolite (for measuring horizontal and vertical angles) and a stadia rod (for measuring distances).
· Advantages of This Method:
· Accurate and efficient for determining elevations, contours, and other topographical details over extensive areas.
· Suitable for mapping hilly and undulating terrains.