Final answer:
A decommissioned nuclear power plant has to go through a process that ensures it does not pose any future public health risks, which includes cleaning up of radioactive contamination and removing radioactive fuel.
Step-by-step explanation:
When considering the statement regarding a decommissioned plant, it is essential to understand what decommissioning involves. Decommissioning a nuclear reactor means that the plant must go through a strict process managed by the U.S. Nuclear Regulatory Commission that ensures the safety removal of the reactor and any equipment that has become radioactive. Thus, a decommissioned nuclear power plant must not pose any danger to public health in the future, which addresses the cleanup of radioactively contaminated plant systems and structures, and the removal of the radioactive fuel
Therefore, the correct answer to the question is that a decommissioned plant must pose no danger to future public health, which aligns with option b: must pose not danger to future public health.