A technician is building a workstation with a liquid all-in-one (AIO) CPU cooler. The motherboard has several 4-pin fan headers labeled CPU_FAN, CPU_OPT, AIO_PUMP, and SYS_FAN. To ensure the cooler's pump runs at a constant full speed and the system does not trigger a fan-error warning at boot, where should the technician connect the pump's power lead?