Explanation:

Earth’s Magnetism: Earth's magnetism is indeed an indirect source of information about the Earth's interior. The magnetic field is generated by movements and convection currents in the Earth's outer core, which is composed of molten iron and nickel. Studying Earth's magnetism can provide insights into these processes and the structure of the Earth's core.

Gravitational Force: Gravitational force, or variations in Earth's gravity, can also be an indirect source of information about the Earth's interior. Gravitational field measurements can reveal differences in the distribution of mass within the Earth, such as the density and thickness of the Earth's crust and mantle.

Volcanic Eruption: Volcanic eruptions provide indirect information about the Earth's interior. Through eruptions, materials from deep within the Earth, like magma and volcanic gases, are brought to the surface. Studying these materials can give scientists valuable information about the composition and conditions deep within the Earth.

All three listed items are indirect sources of information about the interior of the Earth