Which ruling did the United States Supreme Court have in Gideon v. Wainwright?
A. The Sixth Amendment's guarantee of the right to counsel applies only in civil cases.
B. Police officers are allowed to question suspects even if there is no lawyer present.
C. All criminal defendants are entitled to a lawyer, regardless of their ability to pay.
D. Judges in federal courts may not deny a defendant's right to counsel, but state judges
may.