What did the accident at the nuclear power plant in Chernobyl in 1986 demonstrate about the use of nuclear power that had not been previously demonstrated?

The 1986 Chernobyl accident released radioactive material over a wide region, demonstrating that a nuclear power accident could contaminate large areas with radiation. Radioactive fuel and radioactive byproducts were already known features of nuclear power, so choices A and C were not new demonstrations. The correct choice is “Large areas can be contaminated with radiation.”

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