What is the common characteristic of the chemical substances generally known as CL- 20, HMX and LLM-105, which are sometimes talked about in media?

1. A

   These are alternatives to hydro- fluorocarbon refrigerants

   Alternatives to hydrofluorocarbon refrigerants. Those substitutes are a different family (HFOs and similar). CL-20, HMX and LLM-105 are energetic nitramines, not cooling gases.

2. B

   These are explosives in military weapons

   Explosives in military weapons. CL-20 (hexanitrohexaazaisowurtzitane), HMX (octogen) and LLM-105 are high-energy nitramine explosives used in munitions. That is the shared characteristic.

3. C

   These are high- energy fuels for cruise missiles

   High-energy fuels for cruise missiles. These compounds are explosives, not cruise-missile propellants. HMX can appear in some energetic fills, which is why this option sits next to the key.

4. D

   These are fuels for rocket propulsion

   Fuels for rocket propulsion. HMX is used in some rocket propellant grains. CL-20 and LLM-105 are classed as explosives, not a shared rocket-fuel family.

Summary. Official key is (b): CL-20, HMX and LLM-105 are military high explosives. They are not HFC refrigerant substitutes. Rocket or cruise-missile fuel is the neighbour trap because HMX also appears in some propellant grains.