The three correct answers that describe the differences between solar wind and geomagnetic storms are:
1. **Geomagnetic storms occur only occasionally; solar wind is constant.**
2. **Geomagnetic storms are associated with CMEs; solar wind is associated with the constant activity in the sun.**
3. **Solar wind sometimes results in geomagnetic storms; geomagnetic storms do not cause solar wind.**
These statements highlight the differences in frequency, association with solar phenomena, and the causal relationship between solar wind and geomagnetic storms.