The other materials – 75 miles of water pipe, 10 million bricks, 1,172 miles of wire for elevator cable, 50 miles of radiator pipe, more than 6,000 windows, 2 million feet of electrical wire, and 200,000 cubic feet of stone – went up by derrick sling or by elevator directly to the floor where it was scheduled to be used. A temporary, small narrow-gauge track system was installed on each floor as it was needed. —The Building of Manhattan,
Donald A. Mackay

Which sentence paraphrases the last sentence in this passage?

Materials were moved by a derrick sling or an elevator based on where they needed to go.
A track was installed as needed.
A temporary, small narrow-gauge track system was installed on each floor as it was needed.
A track system was temporarily placed on each floor.