What causes the earth’s magnetic field?
A.
the mineral composition of the earth’s crust
B.
currents in the earth’s liquid-metal outer core
C.
molten material in the mantle
D.
magnetic particles located at the earth’s poles
A.
the mineral composition of the earth’s crust
B.
currents in the earth’s liquid-metal outer core
C.
molten material in the mantle
D.
magnetic particles located at the earth’s poles