One of the factors that can change the evacuation area is:

• A. Firefighters entering incidents from the north.
• B. The number of firefighters with self contained breathing apparatus.
• C. The number of firefighters responding to the incident
• D. A change in wind direction

Answer: (D)

The main idea here is how a hazardous release disperses in the environment. The evacuation area is shaped by where the contaminant can travel, which is governed by wind and weather conditions. When the wind direction changes, the plume can shift its path, causing the affected area to move, grow, or shrink. That makes wind direction a dynamic factor the incident team must continually monitor to keep people safe.

The other factors don’t influence how far or where the release spreads. The number of firefighters or whether they have SCBA affects responder safety and operations, not the actual dispersion of the hazard. Similarly, the direction firefighters enter from doesn’t change the plume’s movement. It’s the wind direction change that directly alters the evacuation boundary.