With which agency must scatterings of cremated human remains at sea be filed?

The correct choice is the Environmental Protection Agency (EPA). When scattering cremated human remains at sea, regulations require that these actions comply with specific guidelines to protect the marine environment. The EPA is responsible for overseeing the dumping of materials into U.S. waters under the Marine Protection, Research, and Sanctuaries Act. This act mandates that the scattering of ashes must be reported to ensure that it is conducted in a manner that does not harm marine life or ecosystems.

The importance of filing with the EPA lies in its role in environmental protection and management of oceanic resources. This ensures that the scattering adheres to legal protocols to maintain the health of the oceans. Other agencies mentioned do not possess the regulatory authority or guidelines specific to the scattering of cremated remains at sea.