Which of the following is not one of the three statutory responsibilities of a U.S. attorney?

The representation of the U.S. government before the U.S. Supreme Court in all appeals of federal criminal cases is not one of the three statutory responsibilities of a U.S. attorney. U.S. attorneys serve primarily as the chief federal prosecuting officers and are responsible for prosecuting federal offenses, handling civil litigation involving the federal government, and representing the interests of the United States in the courts.

While U.S. attorneys play a pivotal role in federal case prosecution and legal advisement to federal agencies, particularly in regards to criminal matters, their role does not extend to automatic representation in all Supreme Court appeals. Such representation typically falls to the Solicitor General of the United States, who is specifically tasked with deciding whether to appeal cases before the Supreme Court and representing the government in those proceedings. Consequently, this distinction clarifies that U.S. attorneys are not mandated to represent the government in every appeal, particularly at the level of the Supreme Court.

This understanding positions option A as the correct choice, as it accurately reflects the delineation of responsibilities within the federal legal framework.