How does Earth's internal structure contribute to its magnetic field?
A. The inner core is a permanent magnet made of iron, and the liquid
iron in the outer core aligns with that magnet's magnetic field.
B. Convection currents in the core generate a magnetic field, which is
strengthened by convection currents in the mantle.
C. The crust becomes magnetic because of radiation from the sun,
and the resulting magnetic field makes all of Earth's layers
magnetic
O D. Convection currents in liquid iron in the outer core generate an
electric current, which produces a magnetic field.