A series of consecutive blocks.

• A. Block
• B. Absolute Block
• C. Block Signal System
• D. Track Car

Answer: (C)

In railroad signaling, the track is divided into blocks to protect trains as they move. A series of consecutive blocks is the setup that the block signal system manages—the overall arrangement of signals and interlocking that governs movement across multiple blocks. This isn’t just one block or a specific operating rule; it’s the complete system that ensures trains proceed safely from one block to the next, with signals coordinating entry and occupancy. An absolute block is a stricter rule within this broader concept, requiring trains to stop at red signals, but the idea of multiple blocks in a row is describing the block signal system itself. A single block is just one segment, and a track car is simply a maintenance vehicle, not the signaling arrangement.