During which phase of a trial does the accused formally plead to the charges?

The accused formally pleads to the charges during the arraignment phase of a trial. This is a critical step in the legal process where the defendant is presented with the charges brought against them and is given the opportunity to enter a plea. The possible pleas include guilty, not guilty, or no contest. The arraignment serves as the formal introduction of the case to the court and allows the defendant to understand the specific allegations they are facing.

In contrast, the trial phase involves presenting evidence and arguments to determine the verdict but does not include entering a plea. Sentencing occurs after a guilty plea or a conviction during the trial, where the court imposes a penalty. The appeal phase follows a trial and involves reviewing the case for legal errors but does not involve pleading to charges. Therefore, the arraignment is distinctly the phase designated for the formal plea, making it the correct answer.