Correct Option
Firoz Tughlaq established the Diwan-i-Bandagan, a separate department dedicated to the welfare, employment, and training of slaves. This institutionalized system involved employing a large number of slaves in various state activities, including administration, public works, and agricultural projects. His policy aimed at integrating slaves into the state structure and society, moving beyond their traditional role as personal servants.
Incorrect Options
Option 1: The Ariz-i-Mamalik (Department of Military Affairs) was established and formalized by Balban, not Alauddin Khalji. This department existed prior to Alauddin Khalji's reign.
Option 2: The system of branding horses (Dagh) and maintaining descriptive rolls of soldiers (Chehra) was introduced by Alauddin Khalji, not Balban.
Option 3: Muhammad Bin Tughlaq was succeeded by his cousin, Firoz Shah Tughlaq, not his uncle.