To supply power to the low-voltage outputs of the Secondary Distribution Center, what must happen first?

To supply power to the low-voltage outputs of the Secondary Distribution Center, the first crucial step is for the voltage to be reduced appropriately to a level that the center can handle. The mention of a transformer, specifically the 150 kVA transformer, indicates that it is responsible for stepping down the high voltage, making it suitable for the low-voltage system. This process ensures that the distribution center receives the correct voltage supply that meets operational requirements.

Using a 150 kVA transformer, which is designed to reduce higher voltage levels step-by-step, enables the Secondary Distribution Center to function effectively without risking damage from excess voltage. The other options do not correctly reflect the necessary initial step of voltage reduction before the power can be supplied safely to the low-voltage outputs.