What does a sign that indicates 'Two-way traffic' inform drivers?

Answer: B — Traffic moves in both directions

A sign indicating 'Two-way traffic' is crucial for informing drivers that vehicles are approaching from both directions on the roadway. This type of sign acts as an alert to enhance awareness and caution among drivers, particularly in areas where they might expect one-way traffic. Recognizing that traffic flows in both directions is essential for a safe driving experience, as it requires drivers to remain vigilant for oncoming vehicles and to navigate their movements accordingly. In contrast, signs that suggest a single direction of traffic would typically result in confusion if misinterpreted. Additionally, the options regarding U-turns or parking are not directly related to the primary function of a 'Two-way traffic' sign, which is focused solely on the direction in which vehicles may travel. Therefore, understanding this sign is fundamental for adapting driving behavior to ensure safety on roads marked for two-way travel.