From left to right, which is a proper sequence of the ME-23 brake valve positions?

The correct sequence of the ME-23 brake valve positions is significant for the proper functioning of train braking systems. In this context, the sequence starts with the "Release" position, which allows air to flow into the brake cylinders, effectively releasing the brakes and preparing the train for movement. Following this, the "Electric Holding" position is used to maintain the brakes in a released position once the train is stopped, particularly when power is supplied, preventing any accidental movement.

Next in the sequence is the "Service" position, which engages the brakes without applying them fully, allowing for smooth deceleration during regular operation. Finally, the "Emergency" position is used in critical situations where immediate and full application of the brakes is necessary to bring the train to a stop as quickly as possible.

This sequence is essential for safe and effective train operations, ensuring that a conductor or operator can transition between braking states as required for various operational scenarios. The other options do not accurately reflect the correct flow and usage of the ME-23 brake valve, either placing the positions out of order or including incorrect or misleading positions.