Which of the following characteristics best distinguishes Mauryan royal architecture from pre-Mauryan architecture in the Indian subcontinent?

मौर्य राजकीय स्थापत्य को उप-मौर्य कालीन स्थापत्य से अलग करने वाली विशेषता कौन-सी है?

The most distinctive feature of Mauryan architecture is the monolithic polished stone pillars, which were absent in pre-Mauryan times. These pillars were carved from a single piece of sandstone and had a highly lustrous finish, known as Mauryan polish. This technique required advanced skill and iron tools. The pillars bear inscriptions of Ashoka's edicts in Brahmi script. In contrast, pre-Mauryan architecture predominantly used mud bricks. Although iron tools were also used in the Mauryan period, they are not a defining characteristic. Domed roofs emerged later in post-Mauryan religious structures. Therefore, the introduction of monolithic polished pillars distinguishes Mauryan royal architecture from earlier traditions.