Which of the Following Is Not One of the Eight

Which of the following is not one of the eight basic puzzles about financial structure?

A) Debt contracts are typically extremely complicated legal documents that place substantial restrictions on the behavior of the borrower.
B) Indirect finance, which involves the activities of financial intermediaries, is many times more important than direct finance, in which businesses raise funds directly from lenders in financial markets.
C) Collateral is a prevalent feature of debt contracts for both households and business.
D) There is very little regulation of the financial system.