Concept:The most destructive effect of a volcanic eruption is the one that causes the greatest irreversible harm to human society and the environment.
Explanation:Volcanic eruptions can cause gas emission, water pollution, and lava flows, which are all harmful.
However, the greatest and most devastating impact is the loss of lives and destruction of property.
Human life cannot be replaced, and the destruction of homes, infrastructure, and livelihoods has long-lasting consequences.
Therefore, loss of lives and property is considered the most destructive effect.
Answer:D. Loss of lives and property