The relative position of sunspots on the surface of the Sun
The short-term stability of Earth’s geomagnetic field✓Respuesta correcta
The short-term stability of the Sun’s magnetic field
The solar radio flux at Boulder, Colorado
Explicación
The K-index is derived from the largest deviation of the horizontal geomagnetic field seen at an observatory during a three-hour interval, so it reports how disturbed the field is right now. It says nothing about the Sun's own magnetic field or about sunspot positions.