<em>Answer:</em> True
Although there is a lot we do not know about the Earth, scientists do know why it is that the Earth has a magnetosphere.
The magnetosphere is a region that extends several tens of thousands of kilometers into space, above the ionosphere. It protects the Earth (its upper atmosphere) from cosmic rays and charged particles of solar wind.
When planets are created, the heat causes the different elements to separate into layers. Heavier elements, such as nickel and iron would sink towards the core. Eventually, the pressure that gravity would put on that core would cause it to become solid. However, the outer core stays molten because pressure is not as high. In this molten layer, the differences in temperature and pressure will cause currents, which will move metals around. This generates an electric current that causes magnetic fields.
Because the planet also spins on its axis, it helps align all the magnetic fields generated, allowing it to extend beyond the surface of the planet and form a magnetosphere.