Which organization is primarily responsible for oil spill response in U.S. waters?

The U.S. Coast Guard is primarily responsible for oil spill response in U.S. waters due to its established authority and expertise in maritime safety and environmental protection. This agency is tasked with maintaining the nation's safety and security on the water, which includes overseeing oil spill prevention and response efforts. The Coast Guard operates under the Oil Pollution Act of 1990, which mandates federal response capabilities for oil spills occurring in navigable waters, ensuring a coordinated response to mitigate environmental damage.

In this role, the Coast Guard works closely with other federal, state, and local agencies, as well as private sector organizations, to effectively manage and respond to oil spill incidents. They conduct training exercises, maintain response equipment, and develop response plans that are crucial for minimizing the impact of spills on marine and coastal ecosystems. This central role is part of their broader mission to protect the maritime environment and ensure the safety of navigable waters.

Other organizations mentioned in the choices may have roles related to emergency management or national security, but they do not specialize in oil spill response like the U.S. Coast Guard does.