Final answer:
The head of a hydraulic-operated tool weighs approximately 30 lbs.
Thus, the correct option is C.
Step-by-step explanation:
To determine the force exerted by hydraulic systems, the principles of pressure and mechanical advantage are applied.The weight of the head of a hydraulic-operated tool can vary depending on the specific tool.
However, since the question asks for an approximate weight, we can assume a typical range of weights. The head of a hydraulic-operated tool usually weighs between 20 and 30 lbs.
Therefore, the correct option would be c. 30 lbs.