Explanation: The Delhi Sultanate was a period of significant urban development in the region of Delhi, with several cities being built by different sultans over the course of the 13th to 16th centuries. Each of these cities played a crucial role in the history of Delhi and the Delhi Sultanate.
1. **Kuhana (Delhi-I)**: Kuhana, also known as Lalkot, was the first city built by the Delhi Sultanate. It was founded by Qutb-ud-din Aibak, the first sultan of the Delhi Sultanate, in the early 13th century. Kuhana was strategically located and served as the capital during the early years of the Delhi Sultanate. The city was named after the Kuhana tribe, and it was here that the famous Qutub Minar was constructed.
2. **Siri**: Siri was the second city built by the Delhi Sultanate, constructed by Alauddin Khilji in the late 13th century. Alauddin Khilji was a powerful ruler who expanded the Delhi Sultanate's territory significantly. Siri was known for its strong fortifications and grand palaces, reflecting the power and wealth of the Khilji dynasty. The city was designed to be a secure and impressive capital, and it remained the capital during the reign of Alauddin Khilji and his successors.
3. **Jahanpanah**: Jahanpanah was built by Muhammad bin Tughluq in the 14th century. Muhammad bin Tughluq was a visionary ruler who sought to protect the older cities of Siri and Quila Rai Pithora from Mongol invasions. Jahanpanah, which means "Refuge of the World," was strategically located between Siri and Quila Rai Pithora. The city was designed to be a fortified refuge and a symbol of the Tughluq dynasty's power and resilience.
Each of these cities was built to serve as the capital of the Delhi Sultanate at different times, reflecting the changing needs and ambitions of the ruling sultans. The construction of these cities also demonstrates the architectural and urban planning skills of the Delhi Sultanate, as well as the strategic importance of Delhi as a center of power in medieval India.
Therefore, the correct answer is (D) ALL OF THEM, as all the cities mentioned were indeed built by the Delhi Sultanate in Delhi. Understanding the historical context and the reasons behind the construction of these cities is essential for comprehending the development of Delhi during the Delhi Sultanate period.