The correct option is Ashoka.
Explanation
The Lion Capital at Sarnath is the most celebrated example of Mauryan art and architecture. It serves as the crowning piece of an Ashokan pillar, characterized by its highly polished sandstone surface and symbolic iconography.
Historical Context and Patronage:
- Ashoka: The capital was commissioned by Emperor Ashoka (r. c. 268-232 BCE) to mark the site of the Buddha's first sermon, an event known as Dharmachakrapravartana. The sculpture features four Asiatic lions standing back-to-back on an abacus adorned with a bull, a horse, an elephant, and a lion, resting on an inverted bell-shaped lotus.
- Chandragupta Maurya: As the founder of the Mauryan Empire, his reign focused on consolidation and administration. The tradition of erecting monolithic stone pillars with animal capitals is distinct to the Ashokan era.
- Bindusara: While he expanded the empire, the specific architectural legacy of stone pillars and edicts is not attributed to his patronage.
- Brihadratha: He was the last Mauryan ruler and is not associated with the construction of the major artistic monuments of the dynasty.
Key Takeaway: The Lion Capital at Sarnath is a masterpiece of Mauryan sculpture attributed to Emperor Ashoka and has been adopted as the National Emblem of India.