Task: songer_casetyp1_7-3-3

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 - commercial disputes". 

PER CURIAM.
This case was heard upon the record, briefs and argument of counsel for the respective parties;
And it appearing that the only material factual issue presented by the pleadings is whether the First Baneredit Corporation, from whom the appellee United States acquired the negotiable promissory note herein sued on, acquired the note from the payee before maturity so as to make it a holder in due course not subject to the defenses alleged in appellants’ answer; Schaffer v. United States, 6 Cir., 216 F.2d 330;
And appellee having filed in support of its motion for summary judgment the affidavit of the Secretary of the First Bancredit Corporation stating that it purchased the note from the payee on January 15, 1940, which was prior to the due date of the first installment payment and said affidavit being uncontradicted and not discredited by appellants, and no showing having been made by appellants that there is any evidence now known to them that would in any way contradict said affidavit;
It is ordered that the judgment of the District Court in favor of the appellee for the unpaid balance on the note, be affirmed. Appolonio v. Baxter, 6 Cir., 217 F.2d 267, 271; Gifford v. Travelers Protective Association, 9 Cir., 153 F.2d 209, 211; Zampos v. U. S. Smelting, Refining & Mining Co., 10 Cir., 206 F.2d 171, 174.

Question: What is the specific issue in the case within the general category of "economic activity and regulation - commercial disputes"?
A. contract disputes-general (private parties) (includes breach of contract, disputes over meaning of contracts, suits for specific performance, disputes over whether contract fulfilled, claims that money owed on contract) (Note: this category is not used when the dispute fits one of the more specific categories below)
B. disputes over government contracts
C. insurance disputes
D. debt collection, disputes over loans
E. consumer disputes with retail business or providers of services
F. breach of fiduciary duty; disputes over franchise agreements
G. contract disputes - was there a contract, was it a valid contract ?
H. commerce clause challenges to state or local government action
I. other contract disputes- (includes misrepresentation or deception in contract, disputes among contractors or contractors and subcontractors, indemnification claims)
J. private economic disputes (other than contract disputes)
Answer:

Answer: D