Which signal indicates the end of the Manual Block System?

Answer: A — End of Block Sign

The signal that indicates the end of the Manual Block System is the End of Block Sign. This sign serves a crucial function in signaling to train operators that they are leaving a manual block section, which is a segment of track where train movements are controlled manually to ensure safety. The End of Block Sign also provides important information regarding control over train movements in the following sections, typically where automatic signaling may take over or where manual procedures no longer apply. Understanding the role of the End of Block Sign is essential for safely navigating manual and automatic signaling systems in railway operations. It's designed to clearly delineate control boundaries, ensuring that operators are aware of their jurisdiction and that they can adjust their operations accordingly as they transition from one signaling system to another.