The correct option is Voussoirs.
Explanation
The arcuate style of architecture, introduced prominently in India during the Delhi Sultanate period, is characterized by the use of arches, domes, and vaults. Unlike the trabeate style (which uses lintels and beams), the arcuate style relies on the distribution of weight through the curvature of an arch.
Analysis of Terms:
- Voussoirs: These are the wedge-shaped interlocking blocks of stone or brick used to construct a true arch. They are arranged in a curved line, and the pressure is distributed from the center outwards. The central voussoir at the apex of the arch is specifically known as the keystone, which locks the other blocks in place.
- Squinches: A squinch is a construction, such as a small arch or corbelling, built across the upper corners of a square room to convert it into an octagon, thereby providing a base for a spherical dome.
- Pendentives: These are curved triangular segments of a sphere that allow a circular dome to be placed over a square room. They serve a similar structural purpose to squinches but are geometrically distinct.
- Spandrels: This refers to the roughly triangular space between the outer curve of an arch and the rectangular frame or wall enclosing it.
Key Takeaway:
In the construction of a true arch (arcuate style), the voussoirs are the fundamental structural units that transfer the load of the superstructure to the supports, locked in place by the keystone.