The correct answer is B. Chernobyl.
The Chernobyl disaster was a nuclear accident that occurred on April 26, 1986, at the Chernobyl Nuclear Power Plant in Ukraine. It is considered to be the worst nuclear disaster in history, both in terms of cost and casualties. The accident was caused by a flawed reactor design and human error, and it resulted in the release of large amounts of radioactive material into the environment. The Chernobyl disaster had a devastating impact on the health and well-being of the people who were exposed to the radiation, and it continues to have a legacy of environmental contamination.
The other options are incorrect. Washington is the capital of the United States, and it is not known for any nuclear disasters. Bhopal is a city in India that was the site of a chemical disaster in 1984. Japan was the site of the Fukushima Daiichi nuclear disaster in 2011, but this disaster was not as severe as the Chernobyl disaster.