If the Initiator component is missing, which PIES element is absent?

• A. Power Source
• B. Switch
• C. Initiator
• D. Explosive

Answer: (C)

In this framework, PIES stands for Power Source, Initiator, Explosive, and Switch—the four parts that must be present for the system to function. If the Initiator component is missing, the element that is absent is the Initiator itself. The power source, switch, and explosive could be present, but without the triggering Initiator, there is no initiation of the sequence. So the best answer is the Initiator element.