A multiwire branch circuit originates as circuits 1, 3, and 5 from Panel LP-1 and supplies luminaires providing illumination for the first floor in an office building. This circuit must simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates. What is the purpose of this circuit?
1) To provide power to the luminaires
2) To protect the branch circuit from overload
3) To ensure the safety of the building occupants
4) To prevent electrical shock hazards