Final answer:
A red octagon-shaped traffic sign signifies that drivers must come to a complete stop.
Step-by-step explanation:
A red octagon-shaped traffic sign universally means that you must Stop. This sign is used to inform drivers that they must come to a complete stop at the sign before proceeding, ensuring safety at intersections and other road junctures. The correct answer to the question, 'A red octagon shaped sign means...' is B) Stop. Recognizing the shape and color of traffic signs is crucial for obeying traffic laws and maintaining safety on the road.