The cloud dispersion pattern is aka circular and seen when gas released with little or no air movement.

• A. Cloud dispersion pattern
• B. Plume dispersion
• C. Stream dispersion
• D. Pool pattern

Answer: (A)

When there is little or no air movement, a released gas spreads outward from the source in all directions, forming a roughly circular vapor cloud around the release point. This happens because there’s no strong wind to carry the gas in one direction, so diffusion and buoyancy cause it to expand equally in all directions. That circular, cloud-like pattern is the cloud dispersion pattern.

If wind were present and moving, the gas wouldn’t form a circle; it would be carried downwind, creating a plume. Pool pattern describes liquids spreading on a surface, not gases, so it doesn’t fit this scenario.