The correct answer is C: In 1979, a major accident at Three Mile Island caused questions to arise over the use of nuclear energy.
Even though the Three Mile Island accident did not cause deaths nor injuries to plant workers or members of the nearby community and no one was exposed to harmful radiation, public confidence in nuclear energy declined, a lot of people opposed the construction of new plants, and there were several campaigns by anti-nuclear activist groups.
All of this resulted in a significant decline of nuclear construction in the following decades (through 1980s to 1990s): Seven operating reactors at Three Mile Island were shut down immediately, the NRC (Nuclear Regulatory Commission) did not issue any reactor construction permits, approval for new plants by the NRC was delayed for years and a lot of orders and projects were cancelled (For example: utilities companies canceled over 120 reactor orders because of the soaring costs and stagnating electricity demand)