What are the four types of explosive materials recognized in EOD?

The correct identification of the four types of explosive materials in EOD as high explosives, low explosives, propellants, and pyrotechnics is based on the definitions and characteristics of each category.

High explosives are those that detonate and can produce a shock wave, making them highly destructive. They are often used in military applications and demolition. Low explosives burn rapidly and are used in applications such as blasting and fireworks. Propellants are classified under low explosives but specifically refer to materials used to propel projectiles in firearms and rockets. Pyrotechnics encompass a variety of materials that produce visible or audible effects, often seen in flares and fireworks.

The other options may describe various materials or classifications but do not align with the fundamental types recognized in explosive ordnance disposal. Granular, gaseous, liquid, and solid refer to physical states rather than the chemical behavior and applications of explosives. Military grade, civilian grade, commercial, and illegal categories are based on legality and intended use rather than the intrinsic properties of the explosives themselves. Meanwhile, tracers, detonators, cord, and explosives represent specific components or applications rather than broad classifications of explosive materials.