A train must not enter or foul ABS territory without:

• A. Proceed indication on a controlled signal OR verbal permission of the dispatcher
• B. A stop signal
• C. Verbal permission only
• D. A proceed indication only

Answer: (A)

In ABS territory, authorization to enter or foul a block must come from one of two sources: a proceed indication shown by a controlled signal, or verbal permission from the dispatcher. This ensures the track is clear and protected before you occupy or foul the block. If there is a stop signal, you may not enter regardless of other factors, and you cannot rely on only verbal permission or only a proceed indication in a situation where the other form is actually what's available; the rule is satisfied as soon as either method provides clearance. The option that mentions both of these authorized paths—proceed indication on a controlled signal or dispatcher’s verbal permission—best captures the required authority to enter ABS territory.