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 organization or association", specifically "business, trade, professional, or union (BTPU)". Your task is to determine what subcategory of private association best describes this litigant.

Opinion:
GENERAL DRIVERS, WAREHOUSEMEN AND HELPERS, LOCAL UNION NO. 89, Plaintiff-Appellant, v. AMERICAN RADIATOR & STANDARD SANITARY CORPORATION, Defendant-Appellee.
No. 14709.
United States Court of Appeals Sixth Circuit.
Nov. 8, 1962.
Ralph H. Logan, Louisville, Ky., Hardy, Logan & Tross, Louisville, Ky., on brief, for appellant.
J. Mack Swigert, Cincinnati, Ohio, S. L. Greenebaum, Louisville, Ky., of counsel, for appellee.
Before CECIL, Chief Judge, MC-ALLISTER, Circuit Judge, and LEVIN, District Judge.
PER CURIAM.
This is an appeal from an order granting summary judgment for the defendant in a suit brought to compel arbitration under section 301 of the National Labor Relations Act, 29 U.S.C. § 185. The sole question is whether the contracts entered into between the plaintiff union and the defendant employer required the employer to arbitrate the change from an incentive pay system to a straight hourly pay system for the plaintiff’s members.
The parties agree that the case is controlled by United Steelworkers of America v. Warrior & Gulf Navigation Co., 363 U.S. 574, 80 S.Ct. 1347, 4 L.Ed.2d 1409. The plaintiff relies particularly on the following expression found on page 582, on page 1353 of 80 S.Ct.:
“An order to arbitrate the particular grievance should not be denied unless it may be said with positive assurance that the arbitration clause is not susceptible of an interpretation that covers the asserted dispute. Doubts should be resolved in favor of coverage.”
The court also said on page 584, on page 1354 of 80 S.Ct.: “A specific collective bargaining agreement may exclude contracting out from the grievance procedure.”
The Master Agreement between the parties contained both an arbitration provision and a no-strike clause. However, paragraph 3-c of the applicable Wage Plan Agreement, entered into subsequently, says in part:
“The Company may cancel any production standard or incentive application when new or changed conditions such as those referred to make it impracticable, in the Company’s judgment, to accurately measure the operation for incentive application. Thereafter, the hourly base rate for the job class to which the job is assigned shall apply.” [Emphasis added.]
Paragraph 4 of the Wage Plan Agreement, which provides that the grievance and arbitration procedures set out in the Master Agreement, shall be utilized only:
“(a) At any time after the initial agreement on the hourly base rate scale referred to in Paragraph 2-e, the accuracy of descriptions and the accuracy of the application of the evaluation factors described in the Job Evaluation Manual to new or changed jobs other than bench-mark jobs; and
“(b) The accuracy of the application of .sound and accepted work measurement techniques to the development of production standards by the Company.”
The language of paragraph 3-c clearly states that the employer’s judgment is controlling as to whether an incentive system should be in effect, and paragraph 4 does not include the dispute in question among the matters which are arbitrable. Therefore, this court holds that under the Agreement, the employer was not obligated to submit to arbitration.
Judgment affirmed.

Question: This question concerns the first listed appellant. The nature of this litigant falls into the category "private organization or association", specifically "business, trade, professional, or union (BTPU)". What subcategory of private association best describes this litigant?

Choices:
Business or trade association
utilities co-ops
Professional association - other than law or medicine
Legal professional association
Medical professional association
AFL-CIO union (private)
Other private union
Private Union - unable to determine whether in AFL-CIO
Public employee union- in AFL-CIO (include groups called professional organizations if their role includes bargaining over wages and work conditions)
Public Employee Union - not in AFL-CIO
Public Employee Union - unable to determine if in AFL-CIO
Union pension fund; other union funds (e.g., vacation funds)
Other
Unclear

Answer: 7