What must be done with all container curtains and restraint bars prior to movement?

Prior to the movement of containers, securing all container curtains and restraint bars is crucial for ensuring the safety and integrity of the cargo. When these elements are properly secured, they help prevent any shifting of the load during transport, which could potentially lead to damage, injury, or accidents. Properly secured curtains and restraint bars ensure that cargo remains stable within the containers, minimizing the risk of items being displaced or causing hazards during movement.

While some other options might seem plausible, having the curtains removed or left unfastened would create significant safety risks by allowing the cargo to shift freely. Merely checking them would not provide the necessary assurance for safe transport. Thus, securing these elements is a fundamental safety protocol during the handling and movement of containers.