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 "federal government (including DC)". Your task is to determine which category of federal government agencies and activities best describes this litigant.

Opinion:
NATIONAL LABOR RELATIONS BOARD, Petitioner, v. CARPENTERS UNION, LOCAL 180, Respondent.
No. 22296.
United States Court of Appeals, Ninth Circuit.
Oct. 22, 1970.
Arnold L. Ordman, Gen. Counsel, Dominick L. Manoli, Associate Gen. Counsel, Marcel Mallett-Prevost, Asst. Gen. Counsel, Paul J. Spielberg and Avrum M. Goldberg, Attys., N.L.R.B., Washington, D. C., Roy O. Hoffman, Director, N.L.R.B., San Francisco, Cal., for petitioner.
Victor J. Van Bourg, of Levy and Van Bourg, San Francisco, Cal., for respondent.
Before BARNES, HAMLEY and HUFSTEDLER, Circuit Judges.
PER CURIAM:
This case is before us upon petition of the National Labor Relations Board to enforce its Supplemental Decision and Order directing respondent Carpenters Union, Local 180, to pay $1,540 to Paul Allen. The award grows out of a back-pay specification and hearing following the entry of a consent decree in this court directing respondent to make Paul Allen whole for wages lost as a result of the union’s unfair labor practice. The Board’s supplemental decision is reported at 175 N.L.R.B. No. 150.
The consent decree established that, on August 31, 1965, respondent wrongfully dispatched one Arthur Cook to a construction project in place of Paul Allen. At the backpay hearing, the General Counsel produced evidence showing that Cook became the senior millwright on the project, and that there was at least one millwright on the project until June 3, 1966. The evidence also indicated that Cook worked on the project through October 8, 1965. No evidence was introduced, however, to show why Cook left work or to show that the contractor did not follow a seniority system in determining layoffs.
The Board held that Paul Allen was entitled to an award based upon the pay he would have received from August 31, 1965, to June 3, 1966, the date the last millwright left the project. The union contends that the award should have been based solely upon the time Cook remained on the project.
The Board is vested with broad discretion in selecting a backpay formula appropriate to the circumstances of a particular ease. N.L.R.B. v. Seven-Up Bottling Co., 344 U.S. 344, 346-348, 73 S.Ct. 287, 97 L.Ed. 377 (1953). Of necessity, the award in many instances may only be a close approximation. “In such circumstances the Board may use as close approximations as possible, and may adopt formulas reasonably designed to produce such approximations.” N.L.R.B. v. Brown & Root, Inc., 311 F.2d 447, 452 (8th Cir. 1963).
Here the award, predicated upon the fact that Allen would have been the senior millwright on the project, was not unreasonable because, absent a showing that the contractor did not follow a seniority system in ordering layoffs, he would have been entitled to work until all millwrights were laid off. See Buncher v. N.L.R.B., 405 F.2d 787, 789-790 (3rd Cir. 1969). Having applied a reasonable formula, the burden was on the respondent union to come forward with evidence to mitigate that liability or to show that the employee in question would have been laid off for economic reasons. See, e. g., Snow v. N.L.R.B., 308 F.2d 687, 695 (9th Cir. 1962); Buncher v. N.L.R.B., supra., 405 F.2d at 789; N.L.R.B. v. Brown & Root, Inc., supra, 311 F.2d at 454.
Here no such evidence was presented.
The Board’s order will be enforced.
. The only -witness called with a knowledge of the contractor’s practices was the contractor’s bookkeeper. When asked if she knew why Cook had left work, she stated that she did not know if he had been fired, quit, or was laid off.

Question: This question concerns the first listed appellant. The nature of this litigant falls into the category "federal government (including DC)". Which category of federal government agencies and activities best describes this litigant?

Choices:
cabinet level department
courts or legislative
agency whose first word is "federal"
other agency, beginning with "A" thru "E"
other agency, beginning with "F" thru "N"
other agency, beginning with "O" thru "R"
other agency, beginning with "S" thru "Z"
Distric of Columbia
other, not listed, not able to classify

Answer: 4