The correct answer is: A. Single phase
Single-phase power is the most common type of power used in residential areas. It is a type of alternating current (AC) power that has two wires, one hot wire and one neutral wire. The hot wire carries the current from the power source to the appliance, and the neutral wire carries the current back to the power source.
Three-phase power is a type of AC power that has three wires, one hot wire, one neutral wire, and one ground wire. The hot wires carry the current from the power source to the appliance, and the neutral wire carries the current back to the power source. The ground wire is used to protect people from electrical shock.
Three-phase four wire power is a type of AC power that has four wires, one hot wire, one neutral wire, one ground wire, and one fourth wire that is used to carry the current from the power source to the appliance. This type of power is used in some industrial applications.
In conclusion, the distributors for residential areas are single-phase.