Correct Answer - Option 3 : Theodolite
Theodolite: For measuring horizontal and vertical angles and taking staff reading.
Explanation:
Instruments used in surveying:
Tape: For linear measurement on ground
Chain: It is used for linear measurements
Tripod: It is used for setting up the instrument on ground
Staff: For taking reading for determination of ground levels.
Clinometer: For vertical angle measurement
Abney level: It is used for measuring slopes and vertical angles.
Pantograph: Used for enlarging the plan
Ghat tracer: Used for determining of gradients
Sextant: For measuring angles from a boat
Fathometer: For measuring depth of water bodies like ocean.
Theodolite: For measuring horizontal and vertical angles and taking staff reading.
Substance bar: For horizontal distance measurement
Cross-staff range finder: To establish right angles
Parallax bar: For displacement measurement from photograph
Tacheometer: For horizontal and vertical distance computation
Planimeter: Used for area measurement