What does the term "due process" ensure?

The term "due process" refers to the legal requirement that the state must respect all legal rights owed to a person. It ensures the fair treatment of individuals under the law, which includes both procedural and substantive rights. Procedural due process focuses on the procedures that must be followed in legal proceedings to ensure fairness, such as the right to a fair trial and the right to be heard. Substantive due process protects certain fundamental rights from government interference.

In the context of the other options, a quick resolution of legal matters does not necessarily guarantee fairness and could lead to injustices if not handled properly. While the rights of defendants are a critical aspect of due process, it is broader and applies to all individuals, not just defendants in criminal cases. The enforcement of harsh penalties goes against the spirit of due process, which emphasizes fair treatment rather than punitive measures without proper legal procedures. Therefore, the correct answer captures the essence of what due process fundamentally guarantees: fair treatment under the law.