Which of the Following Statements Is TRUE of the Walnut

Which of the following statements is TRUE of the Walnut Street Jail?

A) Prisoners were allowed to congregate during the day to work in factories to improve the production of goods.
B) It introduced the idea of releasing offenders on a conditional basis, leading to the development of parole.
C) Prison administrators often put masks on inmates as they moved through the prison, to avoid identification in case they met each other after release.
D) It was an architectural nightmare, built in an octagon with small, dark cells inside the cellblocks to provide solitary confinement and no labor.