Once the Origin,or Epicenter,of the Explosion Has Been Identified,the Investigator

Once the origin,or epicenter,of the explosion has been identified,the investigator should determine what type fuel was employed.How is that done?

A) By conducting an analysis of the chemicals in the air near the explosion site.
B) By comparing the nature and type of damage to the known available fuels at the scene.
C) By analyzing the dirt found at the explosion site.
D) All of the preceding are methods of determining the type of fuel employed.