The correct answer is D) Federal Communications Commission. The Federal Communications Commission (FCC) is the government agency responsible for issuing ship's radiotelephone station licenses in the United States. This is because the operation of radio equipment on ships, including radiotelephone stations, falls under the FCC's jurisdiction and regulatory authority over maritime communications. The other answer choices are incorrect because they are either not government agencies (A - Radio Technical Commission for Marine Services) or do not have the specific authority to issue ship's radiotelephone station licenses (B - U.S. Coast Guard, C - Maritime Mobile Service Commission).