The two basic coins of the Delhi Sultanate, the silver 'tanka' and the copper 'jital', were introduced by:

The two basic coins of the Delhi Sultanate, the silver "tanka" and the copper "jital", were introduced by Iltutmish (ruled 1211-1236).

About the tanka:

• It was a silver coin weighing about 175 grains (about 11 grams).
• It became the standard silver coin of the Sultanate and remained in use for centuries.
• The word "tanka" is related to the Sanskrit "tanka", meaning a stamped coin; it gave rise to the modern word "taka" (the currency of Bangladesh).

About the jital:

• It was a smaller coin made of copper (or billon).
• It was used for everyday small transactions.
• The exchange rate between the tanka and the jital varied; one tanka was generally worth about 48 jitals (or 50 under some rulers).

Features of Iltutmish's coins:

• He introduced the purely Arabic type of coinage, with inscriptions in Arabic.
• His coins carried his name and titles.
• Some of his coins also carried the image of a horseman, continuing an older Indian tradition.
• His coinage reform gave a uniform currency system to the Sultanate.

Importance:

• A standard coinage helped trade and the collection of revenue in cash.
• The tanka and jital became the basis of the monetary system of north India.

Later coinage:

Sher Shah Suri introduced the silver "rupiya" (rupee) and the copper "dam", which were continued by the Mughals.

Iltutmish's other achievements:

• He organised the iqta system and the nobility.
• He completed the Qutub Minar.
• He built the Hauz-i-Shamsi (a reservoir) in Mehrauli.
• He is called the real founder (consolidator) of the Delhi Sultanate.

Why not the other options?

• ✗Qutbuddin Aibak, Balban and Muhammad bin Tughlaq did not introduce these coins.