What name was given to the silver currency minted under the Delhi Sultanate?

The correct option is Tankas.

Explanation:
During the reign of the Delhi Sultanate, Sultan Shamsuddin Iltutmish (1211–1236 CE) of the Slave (Mamluk) Dynasty established a organized coinage system for his empire. The primary silver currency minted under his rule and throughout the Sultanate period was known as the Tanka.

Key highlights of the currency system of the Delhi Sultanate:
• Silver Tanka: A silver coin weighing approximately 175 grains (around 11.3 grams), which served as the official high-value unit of currency.
• Copper Jital: Along with the silver Tanka, Iltutmish introduced a small copper coin called the Jital, used for daily low-value transactions.

Context of Other Options:
• Mohurs: Gold coins introduced later in medieval India by Sher Shah Suri and extensively minted during the Mughal Empire.
• Pagodas: Gold currency coins issued by various South Indian dynasties, most notably the Vijayanagara Empire.
• Dinars: Gold currency coins widely used across the historical Islamic caliphates in the Middle East and Central Asia.