What are the two main ways that scientists learn about Earth's interior and what do these two things indicate?

Scientists use seismic waves from earthquakes to study the interior and the Earth's magnetic field. The seismic waves indicate the mantle is molten rock that flows like plastic, the outer core is completly molten rock, and the inner core is a solid ball of iron. The magnetic field indicates the inner core is spinning faster than the rest of the planet

Is it multiply choice?