Sultan Iltutmish won universal respect for constructing a large reservoir just outside Dehli-i kuhna. It was called the hauz-i Sultani or the 'King's Reservoir'.

Answer:

To answer this question, it is important to understand the historical context and the accomplishments of Sultan Iltutmish.

Historical Context:
Sultan Iltutmish was the third ruler of the Delhi Sultanate, which was established in 1206 after the death of Qutb-ud-din Aibak. Iltutmish ascended to the throne in 1211 and ruled until his death in 1236. He is considered one of the most powerful and influential rulers of the Delhi Sultanate.

Accomplishments of Sultan Iltutmish:
During his reign, Sultan Iltutmish made significant contributions to the administration, military, and infrastructure of his empire. One of his notable achievements was the construction of a large reservoir just outside Delhi-i Kuhna, which is now known as the Hauz-i-Iltutmish.

Construction of the Reservoir:
The reservoir, Hauz-i-Iltutmish, was built during the early years of Sultan Iltutmish's reign. It was constructed to address the water scarcity issues faced by the residents of Delhi. The city of Delhi had limited water resources, and there was a need for a reliable water supply for the growing population.

The reservoir was built by constructing a dam across a natural stream called the Yamuna River, which flowed near Delhi-i Kuhna. The dam successfully captured and stored water from the river, creating a large artificial lake. This reservoir not only provided a regular water supply to the city but also served as a source of irrigation for nearby agricultural lands.

Significance of the Reservoir:
The construction of the reservoir had several significant implications:

1. Water Supply: The reservoir ensured a consistent water supply for the residents of Delhi. It helped to meet the increasing demands of the population and supported the growth and development of the city.

2. Irrigation: The reservoir provided water for irrigation purposes in the surrounding areas. This facilitated agricultural activities and contributed to the economic prosperity of the region.

3. Public Welfare: The construction of the reservoir demonstrated Sultan Iltutmish's concern for the welfare of his subjects. It was a public infrastructure project that aimed to improve the lives of the people by addressing their basic needs.

4. Architectural Marvel: The Hauz-i-Iltutmish is not only functional but also architecturally impressive. It features intricate carvings, decorative elements, and a beautiful pavilion. This reflects the artistic and architectural achievements of the Delhi Sultanate during the 13th century.

In conclusion, Sultan Iltutmish's construction of the large reservoir just outside Delhi-i Kuhna, now known as the Hauz-i-Iltutmish, was a significant achievement. It provided a reliable water source for the city of Delhi, supported agricultural activities, and showcased the architectural prowess of the Delhi Sultanate. Therefore, the correct answer is option 'C' - Delhi-i Kuhna.