Final answer:
Basaltic magma has the lowest viscosity compared to andesitic or rhyolitic magmas, largely due to its higher temperature and lower silica content.
Step-by-step explanation:
The kind of magma with the lowest viscosity is basaltic magma. Viscosity is a measure of a fluid's resistance to flow, with lower viscosity indicating a more fluid state. Basaltic magma, which is associated with oceanic crust, erupts on the seafloor to create basalt lava flows that are in event characterized as being able to flow quickly and move easily over significant distances, often more than 20 kilometers. This low viscosity can be attributed to its higher temperature and lower silica content compared to andesitic or rhyolitic magmas, which have higher viscosity levels. Rhyolitic magma, for instance, is highly viscous, and often associated with the formation of rocks like rhyolite and pumice which have very high silica content and lower temperatures relative to basaltic magma.