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:
QUINN, COMMISSIONER, CHICAGO FIRE DEPARTMENT v. MUSCARE
No. 75-130.
Argued March 30, 1976
Decided May 3, 1976
William R. Quinlan argued the cause for petitioner. With him on the briefs were Daniel Pascóle and Edmund Hatfield.
Linda R. Hirshman argued the cause for respondent. With her on the brief was Robert S. Sugarman.
Briefs of amici curiae urging affirmance were filed by Michael P. Bucklo and David A. Goldberger for the Illinois Division of the American Civil Liberties Union; by Jerry D. Anker for the Coalition of American Public Employees; and by Victor J. Cacciatore for the Chicago Patrolmen’s Assn.
J. Albert Woll, Robert C. Mayer, and Laurence Gold filed a brief for the American Federation of Labor and Congress of Industrial Organizations as amicus curiae.
Per Curiam.
The respondent, a lieutenant in the Chicago Fire Department, was suspended from his job for a 29-day period in 1974 as a result of charges related to his violation of the department’s personal-appearance regulation. Following the suspension, the respondent brought an action in the United States District Court for the Northern District of Illinois seeking an injunction and backpay on the ground that the regulation infringed his constitutional right to determine “the details of his personal appearance.” The department defended the challenged regulation as a safety measure designed to insure proper functioning of gas masks worn by firefighters and as a means of promoting discipline in the department and .the uniform, well-groomed appearance of its members. After a hearing focusing on the operation of the self-contained breathing apparatus used by members of the department, the District Court found that the personal-appearance regulation was justified “on safety grounds” and that the respondent’s goatee violated the regulation. Explaining that the other regulations cited in the discharge notice were not “relevant or pertinent to the issues,” the court denied the respondent’s motion for injunctive relief.
The Court of Appeals for the Seventh Circuit reversed, holding that the respondent “was suspended without procedural due process.” The appellate court concluded that the Constitution requires “that some opportunity to respond to charges against him be made available to the governmental employee prior to disciplinary action against him.” The Court of Appeals did not dispute the District Court’s determination that “the only issue” was whether the suspension for having a goatee was “justifiable under the circumstances.” Although it did not reach the merits of the respondent’s challenge to the constitutionality of the hair regulation, the Court of Appeals did note that the regulation “does not appear to be co-extensive with the need for safe and efficient use of gas masks and, if that is the sole justification, might well be more narrowly drawn.”
Following the grant of certiorari and the oral argument in this case, this Court in another case upheld a police department hair regulation similar to that challenged by the respondent in the present litigation. Kelley v. Johnson, ante, p. 238. In that ease, we concluded that “the overall need for discipline, esprit de corps, and uniformity” defeated the policeman’s “claim based on the liberty guaranty of the Fourteenth Amendment.” Ante, at 246, 248. Kelley v. Johnson renders immaterial the District Court’s factual determination regarding the safety justification for the department’s hair regulation about which the Court of Appeals expressed doubt. Moreover, after the grant of certiorari, this Court was informed that the Civil Service Commission of the city of Chicago had revised its rules to provide for pre-suspension hearings in all nonemergency cases. While this voluntary rule change was subject to rescission, counsel for the petitioner candidly advised the Court at oral argument that even if the petitioner should prevail, it was very doubtful that the Commission would revert to its former suspension procedures.
In view of these developments, the writ of certiorari is dismissed as improvidently granted.
So ordered.
Mr. Justice Stevens took no part in the consideration or decision of this case.
The personal-appearance regulation provided:
“All members of the Chicago Fire Department shall present a clean and proper appearance in personal care and attire at all times. The face shall be clean-shaven, except that a non-eccentric mustache is permissible. Mustaches shall not extend beyond a line perpendicular to the comer of the mouth and the full upper lip must be readily visible. Sideburns shall be trimmed short and shall be no lower than a line from the middle of the ear.
“Hair shall be worn neatly and closely trimmed, and the hair outline shall follow the contour of the ear and slope to the back of the neck. It will be gradually tapered overall, in order to present a neat appearance.” § 51.133 of the Rules and Regulations of the Chicago Fire Department.
The respondent was also charged with conduct unbecoming a member of the Chicago Fire Department, § 61.001, and disobedience of orders, § 61.006, in connection with his failure to conform his appearance to the above regulation.
The respondent contended that the personal-appearance regulation violated his “rights to personal freedom guaranteed by the First, Third, Fourth, Fifth, Ninth, and Fourteenth Amendments.” In addition, he claimed that the regulation proscribing conduct unbecoming a member of the department was vague and overbroad and that his suspension without a prior hearing was unconstitutional.
Although the respondent had not been afforded a pre-suspension hearing he had a right to a post-suspension hearing before the Civil Service Commission. The Commission was empowered to award backpay and to order the deletion of the suspension from the employee’s service record.
Although the new rule was adopted in August 1975, before the grant of certiorari on October 14, 1975, it was first brought to our attention in the respondent’s brief filed on February 4, 1976. The revised procedures providing an opportunity for a pre-suspension hearing apply to all Chicago civil service employees except members of the police department, who are governed by a different set of similar rules.

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