Final answer:
The Court of Appeals does not re-try cases. They review decisions made by district courts and make determinations on whether to confirm, reverse, or remand those decisions, but re-trials are conducted at the district court level.
Step-by-step explanation:
The action that the Court of Appeals does not perform is D. re-try the case. The U.S. Courts of Appeals, sometimes referred to as circuit courts, are intermediate appellate courts. They review the decisions of district courts within their geographic area but do not conduct trials themselves. Their role is to either affirm or confirm the district court's ruling, reverse the district court's ruling, or remand, which means to send the case back for re-trial or reconsideration at the lower court with specific instructions. The actual re-trying of cases is left to the lower trial courts. Therefore, the Courts of Appeals focus on the legal correctness of past proceedings rather than serving as a venue for new trials.