Final answer:
The sign with 'U turn only' indicates that vehicles must make a U-turn from that lane, ensuring traffic flow and pedestrian safety.
Step-by-step explanation:
The sign that has U turn only typically indicates that vehicles must make a U-turn from the designated lane. This would mean option A, vehicles must make a U-turn from this lane, is the correct interpretation. Such signs are important to ensure traffic flow and safety at intersections. It allows for controlled vehicle maneuvers, reducing the likelihood of accidents caused by unexpected turns. Additionally, these signs play a vital role in ensuring pedestrian safety by preventing sudden or unauthorized movements of vehicles that could endanger individuals crossing roads.