What follows is an opinion from the Supreme Court of the United States. Your task is to determine the bases on which the Supreme Court rested its decision with regard to the legal provision that the Court considered in the case. Consider "judicial review (national level)" if the majority determined the constitutionality of some action taken by some unit or official of the federal government, including an interstate compact. Consider "judicial review (state level)" if the majority determined the constitutionality of some action taken by some unit or official of a state or local government. Consider "statutory construction" for cases where the majority interpret a federal statute, treaty, or court rule; if the Court interprets a federal statute governing the powers or jurisdiction of a federal court; if the Court construes a state law as incompatible with a federal law; or if an administrative official interprets a federal statute. Do not consider "statutory construction" where an administrative agency or official acts "pursuant to" a statute, unless the Court interprets the statute to determine if administrative action is proper. Consider "interpretation of administrative regulation or rule, or executive order" if the majority treats federal administrative action in arriving at its decision.Consider "diversity jurisdiction" if the majority said in approximately so many words that under its diversity jurisdiction it is interpreting state law. Consider "federal common law" if the majority indicate that it used a judge-made "doctrine" or "rule; if the Court without more merely specifies the disposition the Court has made of the case and cites one or more of its own previously decided cases unless the citation is qualified by the word "see."; if the case concerns admiralty or maritime law, or some other aspect of the law of nations other than a treaty; if the case concerns the retroactive application of a constitutional provision or a previous decision of the Court; if the case concerns an exclusionary rule, the harmless error rule (though not the statute), the abstention doctrine, comity, res judicata, or collateral estoppel; or if the case concerns a "rule" or "doctrine" that is not specified as related to or connected with a constitutional or statutory provision. Consider "Supreme Court supervision of lower federal or state courts or original jurisdiction" otherwise (i.e., the residual code); for issues pertaining to non-statutorily based Judicial Power topics; for cases arising under the Court's original jurisdiction; in cases in which the Court denied or dismissed the petition for review or where the decision of a lower court is affirmed by a tie vote; or in workers' compensation litigation involving statutory interpretation and, in addition, a discussion of jury determination and/or the sufficiency of the evidence.

Opinion:
WALLING, WAGE AND HOUR ADMINISTRATOR, v. NASHVILLE, CHATTANOOGA & ST. LOUIS RAILWAY.
No. 335.
Argued January 17, 1947.
Decided February 17, 1947.
William S. Tyson argued the cause for petitioner. With him on the brief were Acting Solicitor General Washington, Stanley M. Silverberg and Morton Liftin.
Walton Whitwell argued the cause for respondent. With him on the brief were Edwin F. Hunt and Wm. H. Swiggart.
Lester P. Schoene filed a brief for the Railway Labor Executives’ Association, as amicus curiae, in support of petitioner.
Me. Justice Black
delivered the opinion of the Court.
The petitioner, Administrator of the Wage and Hour Division, United States Department of Labor, filed this action in a Federal District Court to enjoin alleged violations by the respondent railroad of §§15 (a) (2) and 15 (a) (5) of the Fair Labor Standards Act. 52 Stat. 1060, 1068. These sections require that minimum wages be paid to employees covered by the Act and that appropriate records be kept concerning their employment and pay. The railroad was charged with having violated the Act with regard to two types of alleged employees: First, persons in training to become yard and main line firemen, brakemen, and switchmen; second, others in training to become clerks, stenographers, callers, messengers, and other similar general miscellaneous workers. The District Court held that the first group were not “employees” and therefore were not covered by the Act. On this ground alone the injunction was denied as to them. It also denied relief as to the second group, clerks, etc., partly on this same ground. Another ground for denying relief as to the second group was the court’s finding that the railroad “for several years past has been complying with the Act as to them, and apparently intends in good faith to do so in the future.” 60 F. Supp. 1004, 1007-1008. The Circuit Court of Appeals affirmed. 155 F. 2d 1016, one judge dissenting. We granted certiorari because of the importance of the questions decided. 329 U. S. 696.
The finding of the District Court that the railroad had been complying with the Act in good faith in its business relations with the trainee clerks, stenographers, etc. is not challenged. No argument is here made that this is not adequate support for denial of the relief granted as to this second group. Under these circumstances, we affirm the court’s action in denying an injunction to enjoin violations of the Act as to these trainees. We therefore do not reach the question as to whether this group as a whole or any of the persons in it were or were not employees under the Act.
The sole ground for denying relief as to the persons training to become firemen, brakemen, and switchmen was that they were not employees. The findings of fact here as to the training of these trainees are in all relevant respects practically identical with the findings of fact in Walling v. Portland Terminal Co., this day decided, ante, p. 148. These findings of fact are not challenged. For the reasons set out in that opinion we hold that the Circuit Court of Appeals was not in error in holding that the persons receiving training in order to become qualified for employment as firemen, brakemen, and switchmen, are not employees within the meaning of the Fair Labor Standards Act.
Affirmed.

Question: What is the basis of the Supreme Court's decision?

Choices:
judicial review (national level)
judicial review (state level)
Supreme Court supervision of lower federal or state courts or original jurisdiction
statutory construction
interpretation of administrative regulation or rule, or executive order
diversity jurisdiction
federal common law

Answer: 3