Answer :
Final answer:
The correct answer to the question is head stock, which houses the lathe spindle and control levers for speed selection in a lathe machine.
Explanation:
The unit of a lathe which houses the lathe spindle and control levers for speed selection is called a head stock. The head stock is a critical component of the lathe as it contains the motor and gears that provide power to the cutting tool. In operation, the head stock's spindle allows the workpiece to be held securely and rotated at various speeds which are set using the control levers. Other options like tail stock, feed box, and carriage have different functions on a lathe machine.
