Select the correct order of the levels of protection from least protection required to most protection required.

The correct order of levels of protection from least protection required to most protection required is based on the understanding of how various protective measures are implemented in explosive safety. The correct sequence starts with IMD (Initial Mission Defense), which is the least protective level. This is followed by ILD (Intermediate Level Defense), which represents a greater degree of safety than IMD but is not the most comprehensive.

Next in the hierarchy is PTRD (Potential Target Risk Defense), which offers a higher level of protection, focusing on mitigating risks from potential targets associated with explosives. Finally, IBD (Integrated Base Defense) provides the most robust protection, implementing a wide range of safety measures and support to ensure comprehensive security for personnel and property.

This order signifies a progression from basic measures that are taken at the beginning of a mission scenario to advanced, integrated defenses designed to cover all bases in explosive safety management. Understanding this order is crucial for implementing the appropriate level of protection depending on the specific context and risks involved.