The correct answer is B) U.S. Coast Guard. The U.S. Coast Guard, in addition to the National Weather Service, provides plain-language radio weather advisories for the coastal waters of the United States. This is a key responsibility of the Coast Guard, as they are tasked with ensuring the safety of mariners and providing critical weather information for coastal regions. The other options are incorrect, as the U.S. Hydrological Survey, American Meteorological Service, and National Geospatial-Intelligence Agency do not have the primary responsibility for broadcasting these types of weather advisories.