What action must be taken if a defendant wishes to plead not guilty?

When a defendant wishes to plead not guilty, the appropriate action is to plead not guilty in court. This is a fundamental right of the defendant that is enacted during the arraignment phase of the trial process. During this court appearance, the defendant is formally presented with the charges against them and has the opportunity to respond. Pleading not guilty signals to the court and the prosecution that the defendant intends to contest the charges, which sets the stage for the subsequent legal proceedings, including the opportunity for a trial.

This action is crucial because it formally establishes the defendant's position within the legal process. After a not guilty plea is entered, the court will then typically schedule further proceedings, such as pre-trial hearings and the trial itself, where the prosecution must prove the defendant's guilt beyond a reasonable doubt.

The other options do not effectively convey the procedural step required to enter a not guilty plea. Filing an appeal, for example, is relevant after a verdict has been rendered, and submitting a written notice of intent can pertain to various legal processes but is not necessary for a simple plea. Informing the prosecutor verbally may not properly document the defendant's position within the court system, as a formal plea in court is required to ensure the plea is recognized legally.