A regulatory sign containing a red circle with a slash through the middle indicates:

1. That drivers should come to a complete stop.
2. That an action is forbidden. ✓
3. That some drivers should yield to other drivers.
4. That drivers should drive under the speed limit.

Answer: B. That an action is forbidden.

A red circle with a slash through the middle means that an action is forbidden.

Why this is the answer

The handbook's regulation-sign section says some signs place a red circle crossed by a slash over a symbol. It explains that this means an action is not allowed, or that certain vehicles are kept off the road. A right turn is the example given. So the sign tells you something is prohibited, which matches the forbidden-action choice. It is a restriction sign, not a stop, yield, or speed-limit instruction.

Why the other answers are wrong

• A. That drivers should come to a complete stop. — A full stop is described for a YIELD sign when traffic requires it, not as the meaning of the red circle and slash.
• C. That some drivers should yield to other drivers. — Yielding to other traffic is what the handbook describes for a YIELD sign, while the red circle and slash mark a prohibition.
• D. That drivers should drive under the speed limit. — Regulation signs can cover speed rules, but the red circle and slash specifically means an action is not allowed or vehicles are restricted, not that you must drive under the limit.

Remember it

Think of the slash as a cancel mark: whatever symbol it crosses is not permitted.