Which of the following courts is primarily involved in matters of bankruptcy?

Bankruptcy courts are specifically designated to handle cases related to bankruptcy. They operate as specialized courts under the U.S. District Court system, focusing solely on issues such as the filing of bankruptcy petitions, debt restructuring, and the distribution of assets among creditors. The expertise and structured procedures of bankruptcy courts are essential to effectively manage the complexities involved in bankruptcy cases.

In contrast, U.S. District Courts deal with a broader range of civil and criminal cases, but they do have jurisdiction over bankruptcy appeals, not the initial bankruptcy proceedings themselves. Constitutional courts refers to the general federal courts established by the Constitution, which include various types of courts, but again, they are not specific to bankruptcy matters. Appellate courts review decisions from lower courts, including bankruptcy courts, but they do not hear bankruptcy cases directly.

Thus, the correct answer is bankrputcy courts as they are directly tasked with adjudicating bankruptcy issues.