G3A01

How does a higher sunspot number affect HF propagation?

1. AHigher sunspot numbers generally indicate a greater probability of good propagation at higher frequencies
2. BLower sunspot numbers generally indicate greater probability of sporadic E propagation
3. CA zero sunspot number indicates that radio propagation is not possible on any band
4. DA zero sunspot number indicates undisturbed conditions

Pick an answer to check it.