Equipment capable of being propelled by electrical energy through the use of third rail contact shoes.

• A. Engine (ENG)
• B. Track Car (TC)
• C. Block Signal System
• D. Multiple Unit Equipment

Answer: (D)

When a train is powered by energy drawn from the third rail, propulsion comes from traction equipment located in the cars themselves. This is exactly what multiple unit equipment is designed to do: a set of self-contained motor cars, each with traction motors and third-rail contact shoes, that together draw power from the third rail and move as a single train. The power collection and distributed propulsion across the entire consist are the defining features of MU-type electric service, which is why this option is the best fit for equipment that uses third-rail energy.

The other options don’t fit as neatly. An engine typically implies a single locomotive, which, while it can be electric, is not inherently described as a self-contained MU consisting of multiple powered cars. A track car is usually a smaller, sometimes non-standard passenger or maintenance vehicle and isn’t defined by a third-rail propulsion setup. A block signal system is a signaling infrastructure, not a vehicle at all.