What does a solid white line on the road mean?

Answer: C — Lane change is discouraged

A solid white line on the road indicates that lane changes are discouraged. This marking often appears between lanes of traffic going in the same direction and serves as a visual signal to drivers that changing lanes is generally not advisable. It alerts drivers to exercise caution and remain in their lane, typically due to factors such as the presence of a bike lane, the proximity to intersections, or other roadway conditions that might necessitate maintaining lane position for safety. While it is not legally prohibited to change lanes across a solid white line, doing so is discouraged due to potential risks, such as sudden lane shifts that could result in collisions. Hence, drivers should be more vigilant and aware of surrounding traffic before considering a lane change in these scenarios.