What follows is an opinion from a United States Court of Appeals. Your task is to identify the federal agency (if any) whose decision was reviewed by the court of appeals. If there was no prior agency action, choose "not applicable".

Opinion:
Guy T. HELVERING, Commissioner of Internal Revenue, Petitioner, v. W. H. T. FOSTER.
No. 11746.
Circuit Court of Appeals, Eighth Circuit.'
June 6, 1941.
Samuel O. Clark, Jr., Asst. Atty. Gen., Sewall Key, S. Dee Hanson, and F. E. Youngman, Sp. Assts. to Atty. Gen., and J. P. Wenchel, Chief Counsel, Bureau of Internal Revenue, and C. E. Lowery, Sp. Atty., Bureau of Internal Revenue, both of Washington, D. C., for petitioner.
Herbert A. Friedlich, Harry Thom, and Benjamin A. Ragir, all of Chicago, 111., for respondent.
PER CURIAM.
Decision of Board of Tax Appeals reversed on authority of certain decisions of the Supreme Court of the United States, pursuant to motion of counsel for petitioner and concurrence of counsel for respondent, and cause remanded for proceedings in accordance with law.

Question: What federal agency's decision was reviewed by the court of appeals?

Choices:
Benefits Review Board
Civil Aeronautics Board
Civil Service Commission
Federal Communications Commission
Federal Energy Regulatory Commission
Federal Power Commission
Federal Maritime Commission
Federal Trade Commission
Interstate Commerce Commission
National Labor Relations Board
Atomic Energy Commission
Nuclear Regulatory Commission
Securities & Exchange Commission
Other federal agency
Not ascertained or not applicable

Answer: 13