Which of the following Delhi Sultans died while playing polo, also known as chaugan?

Introduction / Context:
Medieval Indian history includes many interesting biographical facts about rulers, some of which are often asked in competitive exams. One such fact concerns a Delhi Sultan who died as a result of a fall while playing polo, or chaugan. This question checks your recall of that specific historical detail regarding the early rulers of the Delhi Sultanate.

Given Data / Assumptions:

• The question is about Delhi Sultans and the game of polo or chaugan.
• Four rulers of the early Sultanate period are provided as options.
• Only one of these rulers is historically linked with the polo accident.

Concept / Approach:
Qutbuddin Aibak was the founder of the Slave or Mamluk dynasty of the Delhi Sultanate. He is historically recorded to have died due to injuries sustained after falling from a horse while playing chaugan. The other rulers listed, such as Iltutmish and Balban, are known for administrative and military actions but not for dying during a game. Recognising this specific incident allows you to select the correct name.

Step by Step Solution:
Step 1: Recall who Qutbuddin Aibak was, including his role as the first ruler of the Slave dynasty. Step 2: Remember that sources describe his death in Lahore after a fall from a horse while playing chaugan. Step 3: Consider the other names: Iltutmish and Balban ruled later and are not associated with death during polo. Step 4: Nasiruddin Muhammad also does not have this specific story attached to his death. Step 5: Based on this, identify Qutbuddin Aibak as the correct answer.

Verification / Alternative check:
History texts on the Delhi Sultanate often include a short note about Aibak's death, mentioning the polo accident. This story is repeated in many exam oriented summaries because it is an easy fact based question. The absence of a similar anecdote for other rulers further confirms that Aibak is the only correct option here.

Why Other Options Are Wrong:
Balban: He is remembered for his strong monarchy and harsh measures, not for dying in a sports accident, so this option is incorrect.
Iltutmish: He consolidated the Slave dynasty and expanded the empire but did not die while playing polo.
Nasiruddin Muhammad: His reign is less famous, and there is no widely accepted account of him dying in a polo related incident.

Common Pitfalls:
Sometimes students mix biographies of early Sultans because many of them belong to the same dynasty. Another mistake is to guess a more familiar name like Iltutmish instead of recalling the specific story. To remember this fact, visualise Qutbuddin Aibak as the ruler who met an accidental death while engaged in a royal game.

Final Answer:
The Sultan who died while playing polo or chaugan was Qutbuddin Aibak.