Correct option is C
The
dumpy level is a precision instrument used for
differential levelling,
reciprocal levelling, and
profile levelling. It works on the principle of establishing a horizontal line of sight to measure the relative heights of different points on the ground.
However,
trigonometric levelling involves the use of angular measurements (vertical angles) in addition to horizontal distances to determine elevation differences, which requires a
theodolite or total station, not a dumpy level.
Therefore, the type of levelling that
cannot be done with a dumpy level is
trigonometric levelling.
