Who introduced the Jail system for detention of prisoners?

Posted by

(a) Hazrat Umar (RA)
(b) Hazrat Abu Bakr (RA)
(c) Hazrat Ali (RA)
(d) Hazrat Khalid bin Waleed (RA)

See also  Which of the following birds conveyed the message of Hazrat Sulaiman (AS) to the?