Who started Public Distribution System in Sultanate period?

Fawazil in the Sultanate period meant :

Who was the first Sultan of Delhi to participate in the public celebration of Holi?

Who created the department of Diwan-i-Arz in Delhi Sultanate?

Which period is called the era of “the rule of the Forty” in the history of Delhi Sultanate age?

Which dynasty of Delhi Sultanate ruled for the shortest period?