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 respondent. The nature of this litigant falls into the category "federal government (including DC)", specifically "other agency, beginning with "F" thru "N"". Your task is to determine which specific federal government agency best describes this litigant.

Opinion:
Andrew J. EASTER and Mildred P. Easter, Petitioners, v. COMMISSIONER OF INTERNAL REVENUE, Respondent.
No. 9602.
United States Court of Appeals Fourth Circuit.
Argued Nov. 16, 1964.
Decided Dec. 1, 1964.
Andrew J. Easter, petitioner, pro se.
Norman Sepenuk, Atty., Dept. of Justice (Louis F. Oberdorfer, Asst. Atty. Gen., Lee A. Jackson and Melva M. Graney, Attys., Dept. of Justice, on brief), for respondent.
Before SOBELOFF, Chief Judge, and BOREMAN and J. SPENCER BELL, Circuit Judges.
PER CURIAM.
We have carefully reviewed the decision of the Tax Court in this matter, and for the reasons set out in its opinion, we affirm.
The adjustment of the depreciation basis for the facilities located at 6608 Belair Road, Baltimore, Maryland,was clearly proper, since it is undisputed that the taxpayer himself invested only $28,000 in the buildings on that site. It is elemental that a taxpayer cannot recoup by means of depreciation deductions an investment in a depreciable asset made by a stranger. Detroit Edison Co. v. Commissioner of Internal Revenue, 319 U.S. 98, 102, 63 S.Ct. 902, 87 L.Ed. 1286 (1943); Commissioner of Internal Revenue v. Revere Land Co., 169 F.2d 469 (3 Cir.), cert. denied, 335 U.S. 853, 69 S.Ct. 82, 93 L.Ed. 401 (1948); Commissioner of Internal Revenue v. Arundel-Brooks Concrete Corp., 152 F.2d 225, 162 A.L.R. 1200 (4 Cir. 1945).
There also was no error in the redetermination of the remaining useful life of the other three pieces of property involved in this litigation, for the Tax Court decisions concerning the structures at both 2801 Adams Mill Road in Washington, D. C., and 6420 Belair Road in Baltimore are supported by substantial credible evidence in the record. Regarding the frame house located at 6502 Belair Road in Baltimore, neither the Government nor the taxpayer produced evidence from which a decision could be made as to its reasonable estimated useful life. Since the Commissioner’s determination in this regard is presumptively correct and the burden is upon the taxpayer to show error therein, Burka v. Commissioner of Internal Revenue, 179 F.2d 483 (4 Cir. 1950), the Tax Court had no choice but to accept the useful life position contended for by the Commissioner, and we have no choice but to affirm.
While it may be somewhat frustrating to the petitioner, the law is nonetheless settled that the acceptance of returns filed by a taxpayer in earlier years and the acquiescence in the taxpayer’s depreciation basis and useful life figures contained therein for the purpose of approving tax refunds will not support an estoppel argument or bar the Commissioner’s action in correcting a mistake in the taxpayer’s prior returns when it is detected by him within the period of limitations. M. Pauline Casey, 38 T.C. 357, 381 (1962); cf. Caldwell v. Commissioner of Internal Revenue, 202 F.2d 112, 115 (2 Cir. 1953).
Affirmed.

Question: This question concerns the first listed respondent. The nature of this litigant falls into the category "federal government (including DC)", specifically "other agency, beginning with "F" thru "N"". Which specific federal government agency best describes this litigant?

Choices:
Food & Drug Administration
General Services Administration
Government Accounting Office (GAO)
Health Care Financing Administration
Immigration & Naturalization Service (includes border patrol)
Internal Revenue Service (IRS)
Interstate Commerce Commission
Merit Systems Protection Board
National Credit Union Association
National Labor Relations Board
Nuclear Regulatory Commission

Answer: 5