“The amendment states but a truism that all is retained which has not been surrendered. There is nothing in the history of its adoption to suggest that it was more than declaratory of the relationship between the national and state governments as it had
been established by the Constitution before the amendment or that its purpose was other
than to allay fears that the new national government might seek to exercise powers not granted, and that the states might not be able to exercise fully their reserved powers.

- United States v. Darby Lumber Co. (1941)

Q: The excerpt refers to which amendment to the U. S. Constitution?

A) Seventh Amendment

B) Eighth Amendment

C) Ninth Amendment

D) Tenth Amendment