What happened in Chernobyl, Ukraine, in 1986? A. The explosion of a nuclear reactor killed 30 people. B. Deadly gases from a pesticide factory killed 20,000 people. C. The dam holding back a toxic waste retention pond failed, flooding 10,000 homes with benzene. D. Uranium seeping out of a mine contaminated the water supply, causing radioactive poisoning in 30% of the city’s residents. Please select the best answer from the choices provided.