Explanation:

- The Stupa at Sarnath is an important Buddhist monument in India. It is closely associated with the Mauryan king, Ashoka, who was known for spreading Buddhism.

- Option 1: Dhauli

- Dhauli is known for Ashoka's rock edicts and the site of the Kalinga War, not for the Stupa at Sarnath.

- Option 2: Dhamekh

- Dhamekh Stupa is located in Sarnath and was indeed commissioned by Ashoka. It marks the site where Buddha delivered his first sermon.

- Option 3: Bharhut

- Bharhut is known for its ancient Buddhist stupa, not built by Ashoka but later expanded upon.

- Option 4: Lalitgiri

- Lalitgiri is an ancient Buddhist complex in Odisha, not directly related to Ashoka or Sarnath.