Volcano heights are measured in kilometers, not centimeters, years or liters. So, the land's height increased from 1.2 to 11 kilometers, supporting a volcanic eruption.
The units must be a measure of distance and relevant to the context of a volcano's height.
Kilometers makes the most sense as volcanoes are measured in kilometers, so the height increased from 1.2 km to 11 km.
Centimeters is too small a unit for a volcano's height, making the change unrealistic.
Years and Liters are not units of distance and are irrelevant to the context.
Therefore, the answer is Kilometers.