Why is the answer not D?

Hi @kristinsmith04, A) Opens a can of worms that suggests that maybe there are or at least could be active volcanoes on Venus, and we’re just not detecting them D) Our premises are about spikes in sulfur dioxide, not long term levels. This also doesn’t have much of an affect as a weakener on the conclusion (that we should not conclude that volcanic activity caused the spike on Venus). This answer choice is about Earth, and doesn’t tie back to Venus in a way that hurts the plausibility of the conclusion. Hope this helps!