What best describes the inner core of the Earth?

The inner core of the Earth is best described as a solid with a radius of approximately 1,200 kilometers. This solid state is primarily composed of iron and nickel and exists under immense pressure, which is why it remains solid despite the extremely high temperatures that can reach up to 5,700 degrees Celsius (10,300 degrees Fahrenheit). The immense pressure found at these depths prevents the iron from melting, even at such high temperatures, making it distinctly different from the outer core, which is in a liquid state. This solid inner core plays a crucial role in Earth's magnetic field generation and influences geological activity.

Other options describe either the incorrect state (liquid) or radius (3,200 km), which do not accurately represent the characteristics of the inner core.