A photoelectric cell installed in an automatically fired auxiliary boiler burner management system __________.

Correct Answer: Option A — opens the burner circuit upon sensing a flame failure

Photoelectric cells monitor the flame's luminosity in the furnace. If the flame is extinguished, the cell detects the loss of light and immediately signals the burner management system to de-energize the fuel solenoid valves. This prevents the accumulation of unburned fuel, which poses a severe explosion hazard.