Science > ~> ~> ~ a volcanic eruption adds carbon dioxide to the air. this is an example of interactions between the 1) atmosphere and geosphere 2) hydrosphere and geosphere 3) hydrosphere and biosphere 4) geosphere and biosphere

The interaction of a volcanic eruption spouting carbon dioxide to the air is an interaction between the atmosphere and the geosphere. A volcanic eruption is an event that occurs in the geosphere. Air is part of the atmosphere. If you look at it logically the only answer would be 1.