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:
HAMMERSTEIN v. SUPERIOR COURT OF CALIFORNIA et al.
No. 421.
Argued March 9, 1951.
Continued March 26, 1951.
Milton A. Rudin argued the cause for petitioner. With him on the brief was Robert E. Kopp.
E. Loyd Saunders argued the cause for respondents. Saul Ross filed a brief for respondents.
Per Curiam.
In this case the respondent Reggie Hammerstein, by her mother and guardian, commenced a paternity action against the petitioner in the Superior Court of California. Petitioner entered a special appearance in that court, alleging that it had no personal jurisdiction over him, as he was a New York resident. He moved to quash the service upon him in New York on the grounds that any judgment obtained against him in this proceeding would deprive him of due process. The motion to quash was denied. The superior court entered judgment for the respondent.
Prior to the entry of the judgment, petitioner filed a petition for a writ of prohibition in the District Court of Appeal. This petition was denied without opinion. The California Supreme Court denied his application for a hearing. After judgment, petitioner filed in the California Supreme Court a petition for a writ of certiorari to review the superior court proceedings. The California Supreme Court denied this petition without opinion. We granted certiorari, 340 U. S. 919 (1951).
Throughout these proceedings, petitioner preserved his federal questions, but since neither of the decisions below was accompanied by an opinion, it is not clear whether the California courts found it necessary to decide any federal question. If their judgments rest upon an adequate state ground, we, of course, will not review those judgments. If the denials of petitioner's applications for review were based upon a determination of the merits of his federal claim, the case will be ripe for our adjudication. In this circumstance, we think it advisable that we adhere to the procedure followed in Herb v. Pitcairn, 324 U. S. 117 (1945).
We will continue the cause for such period as will enable counsel for the petitioner, with all convenient speed, to apply to the appropriate California courts for certificate or other expression, to show whether the judgments herein rest on adequate and independent state grounds or whether decision of the federal question was necessary to the judgments rendered. Cf. Loftus v. Illinois, 334 U. S. 804 (1948); Indiana ex rel. Anderson v. Brand, 303 U. S. 95 (1938).
Cause continued.

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