The correct option is red and buff sandstone with some marble.
Explanation
The Qutub Minar is a quintessential example of early Indo-Islamic architecture, specifically the Mamluk style. Construction was initiated by Qutb-ud-din Aibak and continued by his successor Iltutmish, with later repairs and additions by Firoz Shah Tughlaq and Sikandar Lodi. The choice of building materials reflects the geological resources available in the region and the architectural preferences of the successive rulers.
Detailed Analysis
- Red and Buff Sandstone: The first three storeys of the minaret are constructed entirely of red sandstone. This material was abundant in the region and commonly used in early Sultanate architecture.
- Marble and Sandstone Mix: The fourth and fifth storeys, which were reconstructed and added later (notably during the reign of Firoz Shah Tughlaq after lightning damage), are made of marble and sandstone. This creates a distinct visual contrast with the lower tiers.
- Incorrect Options:
- white marble throughout: White marble throughout is characteristic of later Mughal architecture (e.g., the Taj Mahal), not early Sultanate monuments.
- granite blocks throughout: Granite was not the primary construction material for the Qutub Minar.
- baked brick with lime plaster: While baked brick was used in other regions or structures, the Qutub Minar is a stone masonry structure.
Key Takeaway: The Qutub Minar is primarily constructed of red sandstone (first three storeys), while the upper two storeys (fourth and fifth) incorporate marble alongside sandstone, reflecting later additions by Firoz Shah Tughlaq.