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:
UNITED STATES v. NICHOLS.
No. 3282.
Circuit Court of Appeals, First Circuit.
Oct. 22, 1937.
Joseph M. Jones, Sp. Asst, to Atty. Gen. (James W. Morris, Asst. Atty. Gen., and Sewall Key and Berryman Green, Sp. Assts. to Attorney General, on the brief), for the United States.
• Philip Nichols, of Boston, Mass., for appellee.
Before BINGHAM, WILSON and MORTON, Circuit Judges.
PER CURIAM.
The only point relied upon and presented for our consideration at the argument of this case was whether section 803(a) of the Revenue Act of 1932 (26 U.S.C.A. § 411(c) amending section 302(c) of the Revenue Act of 1926 was constitutional if applied retroactively' to the irrevocable trust here in question, executed in the year 1930, the creator of the trust having died subsequent to the effective date of the Revenue Act of 1932.
We regard the question as concluded by our decision of June 1, 1937, in Welch v. Hassett, 90 F.(2d) 833. We there said (page 840):
“The defendant’s contention that these statutes can have a retroactive effect where there has been an irrevocable transfer of the decedent’s interest during his lifetime, even though he reserves the income of the property so conveyed, cannot prevail in view of the decisions of the Supreme Court above cited, together with Helvering v. St. Louis Union Trust Co., 296 U.S. 39, 56 S.Ct. 74, 80 L.Ed. 29, 100 A.L.R. 1239; Becker v. St. Louis Union Trust Co., 296 U.S. 48, 56 S.Ct. 78, 80 L.Ed. 35, and Helvering v. City Bank Farmers’ Trust Co., supra [296 U.S. 85, 56 S.Ct. 70, 80 L.Ed. 62], If doubt exists as to the construction of these statutes, it should be resolved in favor of the taxpayer. Gould v. Gould, 245 U.S. 151, 38 S.Ct. 53, 62 L.Ed. 211.”
The judgment of the District Court is affirmed.

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