Option c is the correct answer. The heyday of the Wizarat was during the Tughlaq dynasty, when the wazir wielded too much power and prestige. The most notable wazirs of this period was Muhammad bin Tughluq's wazir, Hasan Nizami. These wazirs were responsible for the expansion of the Delhi Sultanate and the implementation of important reforms. However, the power of the wazir also led to corruption and instability, which eventually contributed to the decline of the Tughlaq dynasty.