In the administration of the Delhi Sultanate, which Sultan is primarily credited with organising and developing the iqta system as a regular system of land assignments for military officers?

Introduction / Context:
This question concerns the administrative and revenue arrangements of the Delhi Sultanate, particularly the iqta system. An iqta was a land assignment given to military officers or nobles in lieu of a cash salary. The iqta holder collected revenue from the assigned area and maintained troops for the Sultan. While several rulers modified or used this system, one early Sultan is especially credited with organising it on a regular and systematic basis.

Given Data / Assumptions:
- The question is about the iqta system under the Delhi Sultanate.
- It asks which Sultan is primarily credited with organising and developing this system.
- The options include Iltutmish, Muhammad bin Tughluq, Alauddin Khalji, Balban and None of the above.
- We assume basic knowledge that the iqta system existed in some form earlier but was given a more regular administrative structure by a particular ruler.

Concept / Approach:
Although the idea of giving land revenue assignments to officers was not entirely new, Sultan Iltutmish is widely regarded as the one who consolidated the iqta system in northern India. He distributed territories as iqta to his trusted nobles and clarified the obligations of iqta holders towards the central government. Later Sultans like Alauddin Khalji and Muhammad bin Tughluq made changes in revenue assessment and control but did not originate the basic structure. The correct approach is therefore to recognise Iltutmish as the key organiser of the iqta system in the early Sultanate period.

Step-by-Step Solution:
Step 1: Recall that the Delhi Sultanate depended on a strong corps of Turkish nobles and military officers who needed to be paid and kept loyal. Step 2: Understand that Iltutmish, one of the early and capable Sultans, took steps to stabilise the kingdom and formalise revenue assignments to these officers. Step 3: Recognise that these assignments, called iqta, allowed officers to collect revenue from a specific area in exchange for maintaining troops and supporting the Sultan. Step 4: Note that later rulers, such as Alauddin Khalji and Muhammad bin Tughluq, introduced reforms in price control, revenue rates and administration but are not primarily remembered for originating the iqta system itself. Step 5: From the listed options, identify Iltutmish as the Sultan most commonly credited with organising the iqta system.

Verification / Alternative check:
A good way to verify is to recall standard textbook summaries of the Slave dynasty and the administrative contributions of Iltutmish. They usually state that he completed the work begun by Qutbuddin Aibak, consolidated the Sultanate and organised the iqta system. In contrast, when Alauddin Khalji is discussed, the focus is on market regulations and military reforms, and Muhammad bin Tughluq is linked with unusual experiments like token currency and shifting the capital. Balban is chiefly associated with strengthening the monarchy, not with iqta organisation. This pattern clearly supports Iltutmish as the answer.

Why Other Options Are Wrong:
Muhammad bin Tughluq: Known for various bold experiments like token currency and capital transfer, but not for organising the iqta system from the beginning.
Alauddin Khalji: Famous for his market regulations, revenue reforms and military campaigns, but he built upon, rather than originated, the iqta system.
Balban: A powerful ruler who emphasised royal authority and rigorous court discipline, but again not the primary organiser of the iqta system.
None of the above: This is incorrect because Iltutmish, listed in option A, is in fact widely credited with systematising the iqta arrangements.

Common Pitfalls:
Students sometimes confuse which ruler introduced which institution because many Delhi Sultans carried out important reforms. It is easy to think of Alauddin Khalji or Muhammad bin Tughluq whenever administration or revenue is mentioned. To avoid this, it helps to match each ruler with one or two key contributions: Iltutmish with iqta organisation and consolidation, Alauddin with market control, and Muhammad bin Tughluq with monetary and capital experiments. Once these associations are clear, identifying Iltutmish as the organiser of the iqta system becomes straightforward.

Final Answer:
The Delhi Sultan who is primarily credited with organising and developing the iqta system was Iltutmish.