When does the movement of liquid propane take place in Quadrant 4?

The correct answer is that the movement of liquid propane takes place during daylight hours only. This is significant because the handling and transportation of liquid propane are subject to various safety regulations and considerations that often prioritize daylight operation.

Daylight hours enhance visibility, which is crucial for safety when dealing with hazardous materials like propane. Proper lighting helps prevent accidents that could occur due to misjudgments or unobserved dangers. Additionally, many regulations and industry practices are designed around safety protocols that assert the safest times for transportation and manipulation of propane are during daylight for these clarity and visibility reasons.

The other choices suggest limitations that do not align with standard safety protocols or operational practices regarding the handling of liquid propane. Safety practices typically avoid nighttime operations unless they are essential and properly managed, while weekends may not inherently constrain movement either. The designation of "all hours" also fails to consider the increased safety risks and visibility challenges during nighttime or less favorable conditions.