One function of a replenishing pump installed in many pressure-closed hydraulic systems, is to supply fluid flow to __________.

Correct Answer: Option B — a servo control circuit

Pressure-closed hydraulic systems require a replenishing pump to maintain a positive suction pressure and provide fluid for the servo control circuit. This circuit manages the pump's swashplate angle or tilting box, ensuring the main pump responds accurately to control inputs while preventing cavitation in the main loop.