Which of the Following Is True About How Plea Bargaining

Which of the following is true about how plea bargaining usually works?

A) a defendant waives the right to a jury trial and the judge determines guilt or innocence
B) a defendant who is serving a prison sentence for a crime the defendant was convicted of can get the sentence reduced for good behavior, community service or similar reasons
C) a defendant pleads guilty to the charged crime or to a lesser offense in exchange for receiving a lighter sentence than if the defendant were to be tried and found guilty of the original charges
D) a defendant waives certain constitutional rights in exchange for a lighter sentence.
E) a defendant signs a settlement agreement with the district attorney, the terms of which are not disclosed to the public