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:
CITY OF PHILADELPHIA et al. v. NEW JERSEY et al.
No. 75-1150.
Argued November 3, 1976
Decided February 23, 1977
Herbert F. Moore argued the cause for appellants. With him on the briefs were Arthur Meisel and John R. Padova.
Stephen Skillman, Assistant Attorney General of New Jersey, argued the cause for appellees. With him on the brief were William F. Hyland, Attorney General, and Mark L. First, Deputy Attorney General.
M. Jerome Diamond, Attorney General of Vermont, Benson D. Scotch, Assistant Attorney General, David H. Souter, Attorney General of New Hampshire, and Donald W. Stever, Jr., Assistant Attorney General, filed a brief for the States of Vermont and New Hampshire as amici curiae urging affirmance.
Briefs of amici curiae were filed by Louis L. Meier, Jr., for the American Society of Civil Engineers, and by William C. Brashares for the National Solid Wastes Management Assn.
Per Curiam.
This suit challenges the constitutionality of a New Jersey statute prohibiting any person from bringing into New Jersey “any solid or liquid waste which originated or was collected outside the territorial limits of the State," except garbage to be fed to swine. 1973 N. J. Laws, c. 363. The New Jersey Supreme Court held that the Act was not pre-empted by a federal statute addressing questions of waste disposal, the Solid Waste Disposal Act of 1965, 79 Stat. 997, 42 U. S. C. § 3251 et seq. (1970 ed. and Supp. V), and was not unconstitutional as discriminating against or placing an undue burden on interstate commerce. Hackensack Meadowlands Dev. Comm’n v. Municipal Sanitary Landfill Authority, 68 N. J. 451, 348 A. 2d 505 (1975). We noted probable jurisdiction on April 5, 1976, 425 U. S. 910.
On October 21, 1976, the Resource Conservation and Recovery Act of 1976, 90 Stat. 2795, 42 U. S. C. § 6901 et seq. (1976 ed.), became law. The parties at the Court’s request supplemented their briefs to address the question of the impact of the new federal statute on the New Jersey Act. Appellants argue that the Federal Act displaces the New Jersey law, and appellees argue that it does not preempt or in any way undercut the validity of the New Jersey legislation. While federal pre-emption of state statutes is, of course, ultimately a question under the Supremacy Clause, U. S. Const., Art. VI, cl. 2, analysis of pre-emption issues depends primarily on statutory and not constitutional interpretation. Therefore, it is appropriate that the federal preemption issue be resolved before the constitutional issue of alleged discrimination against or undue burden on interstate commerce is addressed. We think it appropriate that we have the views of the New Jersey Supreme Court on the question whether or to what extent the Resource Conservation and Recovery Act of 1976 pre-empts the New Jersey statute. The judgment of the New Jersey Supreme Court is therefore vacated, and the case is remanded for reconsideration in light of that Act.
So ordered.

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: 2