What follows is an opinion from a United States Court of Appeals.
Intervenors who participated as parties at the courts of appeals should be counted as either appellants or respondents when it can be determined whose position they supported. For example, if there were two plaintiffs who lost in district court, appealed, and were joined by four intervenors who also asked the court of appeals to reverse the district court, the number of appellants should be coded as six.
When coding the detailed nature of participants, use your personal knowledge about the participants, if you are completely confident of the accuracy of your knowledge, even if the specific information is not in the opinion. For example, if "IBM" is listed as the appellant it could be classified as "clearly national or international in scope" even if the opinion did not indicate the scope of the business. 

Your task concerns the first listed appellant. The nature of this litigant falls into the category "private business (including criminal enterprises)". Your task is to determine what category of business best describes the area of activity of this litigant which is involved in this case.

Opinion:
FIREMAN’S FUND INSURANCE COMPANY, Appellant, v. C. S. LEONARD, individually and trading as Leonard Excavating Company, W. W. Wendell Company, Inc., a Pennsylvania Corporation and Agricultural Insurance Company, a New York Corporation.
No. 17170.
United States Court of Appeals Third Circuit.
Argued Sept. 24, 1968.
Decided Oct. 1, 1968.
Robert F. McCabe, Jr., Pittsburgh, Pa., J. M. McCandless, Robert F. McCabe, Jr., Pittsburgh, Pa., on the brief, for appellant.
James C. Larrimer, Dougherty, Lar-rimer, Lee & Hickton, Pittsburgh, Pa., for appellees.
Before BIGGS, FREEDMAN and VAN DUSEN, Circuit Judges.
OPINION OF THE COURT
PER CURIAM.
Fireman’s Fund Insurance Company, a California surety company doing business in Pennsylvania, appeals to this court from the denial of its motion for a new trial in the court below. The facts are as follows.
On December 26, 1963, Stanton Construction Company entered into a written contract with the Lower Yoder Municipal Authority of Cambria County, Pennsylvania, for the construction of a sewage collection system. Pursuant to the contract Stanton gave bonds for the faithful performance of the contract and the payment for materials and labor furnished. Fireman’s Fund was surety on the bonds. The United States made an assessment under Sections 3402-3403 of Chapter 24 (“Collection of Income Tax at Source on Wages”) of the Internal Revenue Code of 1954 (26 U.S.C. §§ 3402-3403 (1958)), against Stanton for the fourth quarter of 1963 and for every quarter of 1964, the last assessment date being November 4, 1964. Notice of liens was filed in the offices of the Prothono-tary and Recorder of Deeds for Allegheny County on November 9, 1964. The United States then executed on Stanton’s assets. It is clear that all interested parties including Fireman’s Fund had notice of the liens when filed.
On November 25, 1964 Stanton was declared in default by the Municipal Authority. At that time Stanton was in possession of pipe and other materials for which payment had not been made. Fireman’s Fund paid the materialmen and by reason of these payments acceded to Stanton’s interest in the materials under the assignment provisions of the bonds. On May 27, 1965 the United States sold the pipe and other materials at public sale to Wendell and Leonard, the new contractors. The Internal Revenue Service thereupon issued a certificate of sale to Wendell and Leonard. Fireman’s Fund objected to these proceedings claiming ownership of the pipe.
The suit at bar is to recover the value of the pipe, Fireman’s Fund contending that the material in question belonged to it by reason of subrogation. The argument is without merit. The federal tax lien was good against all persons having notice of it. See 12A P.S. § 9-401(2) and 26 U.S.C. §§ 6321-6322. Fireman’s Fund is merely a general creditor. Its rights as subrogee did not ripen until the declaration by the Municipal Authority of the default, by which time the federal tax liens had already been filed.
Accordingly, the judgment will be affirmed.

Question: This question concerns the first listed appellant. The nature of this litigant falls into the category "private business (including criminal enterprises)". What category of business best describes the area of activity of this litigant which is involved in this case?

Choices:
agriculture
mining
construction
manufacturing
transportation
trade
financial institution
utilities
other
unclear

Answer: 6