The correct answer is option 3, which states that the reason Chernobyl appears in the news frequently is due to the explosion of a nuclear power station causing radioactive fallout. In 1986, the Chernobyl disaster occurred at the Chernobyl Nuclear Power Plant in Ukraine. It was the result of a catastrophic nuclear accident caused by a reactor explosion, releasing a large amount of radioactive material into the atmosphere. This disaster is considered one of the worst nuclear accidents in history.

The radioactive fallout from the Chernobyl disaster had significant consequences, both in terms of immediate health effects and long-term environmental impact. The contamination affected a large area surrounding Chernobyl, including parts of Ukraine, Belarus, and Russia. The health effects included increased incidence of cancer, particularly thyroid cancer, and other radiation-related illnesses. The environmental impact resulted in the evacuation and abandonment of nearby towns and villages, as well as the creation of an exclusion zone around the reactor site to protect people from ongoing radiation exposure.

Given the magnitude of the Chernobyl disaster and its long-lasting consequences, it continues to be a topic of interest and frequently appears in the news.