In which type of criminal case does a defendant have the right to a jury trial?

The right to a jury trial in criminal cases is primarily governed by the Sixth Amendment of the United States Constitution, which ensures that an accused can have a speedy and public trial by an impartial jury of the state and district wherein the crime was committed. This right is extended to serious offenses.

In the context of the choices given, a defendant indeed has the right to a jury trial in non-petty offenses where the potential sentence exceeds six months. This threshold is significant because, generally, offenses that are considered "petty" (often referred to as misdemeanors with a maximum punishment of six months or less) do not impart a guaranteed right to a jury trial.

Thus, the essence of this rule is that for offenses carrying a more serious potential penalty, the Sixth Amendment guarantees the right to trial by jury, reinforcing the principle of ensuring fairness in serious criminal prosecutions.