Option 1 -> Diwan-e-Khairat literally means "Department of Charity" and was specifically created for welfare of vulnerable sections.
Option 2 -> Foreign affairs were handled by different administrative departments, not Diwan-e-Khairat.
Option 3 -> Military affairs were under Diwan-i-Arz, a separate department.
Option 4 -> Department of correspondence was managed by Diwan-i-Insha.
Hence, Option 1 -> Firoz Shah Tughlaq established Diwan-e-Khairat as a welfare department to provide financial assistance and support to orphans, widows, and poor girls for marriage expenses, reflecting his policy of public welfare and charitable activities -> correct