Which of the following principles is outlined in Article 31?

The correct choice highlights the prohibition of self-incrimination, a fundamental principle established in Article 31. This article is crucial as it underscores the rights of military personnel to be protected from being compelled to testify against themselves in a criminal matter.

This principle ensures that service members are informed of their rights during interrogations, including the right to remain silent and the implications of any statements they may make. Such protections are essential to safeguard the integrity of the justice process within the military, ensuring that individuals are not coerced into providing evidence that could be used against them.

Understanding this provision reinforces the importance of fair treatment in military law and reflects the intersection of constitutional rights with military regulations, highlighting the necessity for service members to be aware of their rights when facing potential legal issues.