Concept:
Surveying instruments are selected according to the type of measurement required.
Step 1: Wye level, dumpy level and farm level are mainly used for leveling work.
Step 2: Leveling instruments are used to determine height differences.
Step 3: A theodolite is specially designed for measuring angles.
Step 4: It can measure both horizontal and vertical angles accurately.
Step 5: Hence, the correct answer is:
\[
\boxed{\text{Theodolite}}
\]