Multiple Choice, Single Answer

Read the passage and answer the question.

When a volcano erupts, it can affect the planet's temperature far beyond the area around the eruption. Large eruptions inject sulphur dioxide high into the stratosphere, where it reacts to form tiny droplets that linger for months or even years. These droplets reflect a portion of incoming sunlight back into space, producing a modest but measurable cooling of the global surface. Ash, by contrast, falls back to the ground relatively quickly and has little lasting effect on climate. The cooling influence eventually fades as the droplets gradually settle, allowing temperatures to return to their previous levels.