1085. Which of the following is a pictured three phase power transformer, usually used to step-down line voltage for supplying reduced voltage lighting circuits

Choice D is correct; it depicts a three-phase power transformer used to step down voltage for lighting circuits. The device features three distinct coil assemblies, a characteristic of three-phase transformers designed to reduce voltage for lighting loads. Other options are incorrect: A is a ballast, B is a single-phase control transformer, and C is a current transformer used for measurement and protection, not power distribution.