Correct option is B
A theodolite is an instrument which is used to measure both horizontal and vertical Angles.
It is also used for many other subsidiary work during surveying such as setting up of intermediate points between inter visible points, establishment of inter visible points, prolonging a line, laying out traverse etc.
Electronic Digital Theodolite:
It is a precision instrument for measuring angles in the horizontal and vertical planes.
Theodolites are mainly used for surveying applications, and have been adapted for specialized purposes in fields like meteorology and rocket launch technology.
