The correct option is Double Dome.
Explanation
The Gol Gumbad in Bijapur is the mausoleum of Muhammad Adil Shah (1627-1657) and represents the zenith of the Bijapur school of Deccan architecture (Provincial Style). It is structurally distinct from the contemporary Mughal style of Northern India.
Analysis of Architectural Features:
- Double Dome (Incorrect/Absent): The Gol Gumbad is famous for its massive single dome, which is one of the largest hemispherical domes in the world. The "double dome" technique (comprising an inner ceiling and an outer shell to enhance height) was a hallmark of the Lodi and Mughal eras (e.g., Humayun’s Tomb, Taj Mahal) but was not utilized in the Gol Gumbad.
- Whispering Gallery (Present): A distinct acoustic feature located at the base of the dome inside the building. Due to the architecture, sound reflects along the wall, allowing whispers to be heard clearly across the diameter.
- Pendentives/Intersecting Arches (Present): The transition from the square hall to the circular dome is achieved through a unique system of eight intersecting arches. These arches act as structural pendentives, supporting the massive weight of the dome without pillars.
- Turrets at Corners (Present): The main cubical structure is flanked by four seven-storied octagonal towers (minarets/turrets) at the corners, each capped by a smaller bulbous dome.
Key Takeaway: The Gol Gumbad is characterized by its colossal single dome and the use of intersecting arches for structural support, distinguishing it from the double-dome tradition perfected by the Mughals.