The most striking feature of the Ashokan pillars is their

The correct answer is: A. monolithic structure

Ashokan pillars are monolithic, meaning they are carved from a single piece of stone. This is a remarkable feat of engineering, and it is one of the most striking features of the pillars. The pillars are also highly decorated, with intricate carvings of Buddhist symbols and scenes. The pillars are a testament to the skill and artistry of the Indian craftsmen who made them, and they are an important part of Indian history and culture.

The other options are incorrect because:

• B. carving: While the carving on the Ashokan pillars is indeed impressive, it is not the most striking feature. The monolithic structure is more striking.
• C. polish: The Ashokan pillars are polished, but this is not the most striking feature. The monolithic structure is more striking.
• D. uniformity of workmanship: The Ashokan pillars are uniformly well-made, but this is not the most striking feature. The monolithic structure is more striking.