Which substance may lower air temperatures after a volcanic eruption?

A. lava

B. sulfur dioxide

C. carbon dioxide

D. water vapor

Sulfure dioxide, i think

Answer: B. sulfur dioxide

When volcanoes erupt they release mixture of gases, and particles in the surrounding air. Gas sulphur dioxide and ash exhibit a cooling effect on the surrounding environment after the volcanic eruption. The gas sulphur dioxide has special property which allows it to reflect the sunlight away from the earth. Sulphur dioxide also reflects other volcanic gases to the atmosphere, hence ensure cooling at the volcanic site.