The magma most likely form a basalt plateau or shield volcano is

a) magma a
b) magma b
c) magma c
d) magma d

b) Magma B

Explanation:

The magma that forms a basalt plateau or a shield volcano is a mafic (basaltic) magma. This magma is low in viscosity, making it very liquid, so when there's an eruption there's lava flows coming down the slopes like rivers, moving relatively fast. This type of magma has low content of silica, which is the reason why it is low in viscosity. The low viscosity also contributes to very small amount of gases in the magma, as the gases can escape from it very easily so they do not come in a situation to be trapped. The low amount of gases means that the volcanoes with this type of magma have calm eruptions, and explosive eruptions are either nonexistent, or extremely rare.