Task: songer_casetyp1_7-2

What follows is an opinion from a United States Court of Appeals.
Your task is to identify the issue in the case, that is, the social and/or political context of the litigation in which more purely legal issues are argued. Put somewhat differently, this field identifies the nature of the conflict between the litigants. The focus here is on the subject matter of the controversy rather than its legal basis.
Your task is to determine the specific issue in the case within the broad category of "economic activity and regulation". 

ORDER AFFIRMING JUDGMENT OF THE DISTRICT COURT.
This is an action for patent infringement, involving the continuous production of large diameter rod stock from nylon, on appeal from the United States District Court for the Eastern District of Michigan, Southern Division. The District Judge, the Honorable Talbot Smith, rendered a comprehensive opinion holding that the claims of patent asserted by plaintiff are invalid for lack of patentable invention and have not been infringed by defendant. The case has been presented to this court upon briefs and oral argument.
Upon consideration, we find no error in the judgment of the District Court. It is ordered that the judgment of the District Court be and hereby is affirmed upon, the basis of the opinion of the District. Judge reported in 220 F.Supp. 563.

Question: What is the specific issue in the case within the general category of "economic activity and regulation"?
A. taxes, patents, copyright
B. torts
C. commercial disputes
D. bankruptcy, antitrust, securities
E. misc economic regulation and benefits
F. property disputes
G. other
Answer:

Answer: A