Final answer:
The sign with a red circle, white dash, and the letters 'DO NOT ENTER' means that you should not enter the road from your current direction, as it may be a one-way road or an exit ramp.
Step-by-step explanation:
The sign you described, a red circle with a white dash and the letters "DO NOT ENTER," is a regulatory traffic sign. Its specific meaning is option B) Don't enter the road from your direction. This sign is typically placed at the entrance to roadways where traffic is prohibited from entering, such as one-way streets or ramps leading in the wrong direction. It is crucial to obey this sign as entering where it is posted can lead to head-on collisions or other serious traffic incidents.