How is long distance radio communication usually affected by the charged particles that reach Earth from solar coronal holes?

Solar coronal holes emit continuous, high-speed streams of charged particles into space, known as solar wind. When these dense streams of particles are directed toward Earth, they collide with our planet's magnetosphere. This collision triggers geomagnetic storms that disrupt the normal, stratified structure of the ionosphere. Instead of cleanly refracting HF signals back to Earth, a disturbed ionosphere absorbs or scatters them, severely degrading or blacking out long-distance HF communications. The incorrect options referencing VHF/UHF ducting are distractors because tropospheric ducting is a weather-related phenomenon occurring much lower in the Earth's atmosphere, making it largely unaffected by space weather and solar particles.