The option that is likely to have the most negative impact on Earth is:
A solar flare as it may harm satellites and aircrafts flying near poles.
Solar flares are intense bursts of radiation from the sun that can result in electromagnetic disturbances, affecting satellite operations, GPS systems, and communication networks. In particular, they can endanger flights at high altitudes, especially near the poles, where the Earth's magnetic field is weaker and allows more solar radiation to penetrate the atmosphere. Thus, the potential for significant harm to both technology and human safety makes this option the most concerning.