The correct option is
1 only
Explanation
The question compares the architectural features of the Sanchi Stupa (Madhya Pradesh), which represents the transition from Mauryan to Post-Mauryan styles, and the Amaravati Stupa (Andhra Pradesh), a masterpiece of the Vengi or Amaravati school of art developed under the Satavahanas and Ikshvakus.
Statement 1 is Correct:
Sanchi Stupa-1 is famous for its four remarkably preserved stone toranas (gateways) located at the cardinal points, which were added during the Satavahana period. In contrast, the Amaravati Stupa has largely been destroyed and dismantled over the centuries. While sculptural depictions suggest it had entrances, the physical structures (gateways or toranas) have disappeared over time, and the site exists primarily as a ruined mound with artifacts housed in museums.
Statement 2 is Incorrect:
A pradakshinapatha (circumambulatory path) is a fundamental element of stupa architecture. The Amaravati Stupa possessed a prominent pradakshinapatha enclosed by a highly decorated vedika (railing). It is factually incorrect to state that it lacked this feature.
Statement 3 is Incorrect:
The Amaravati Stupa is renowned for its artistic grandeur, specifically the extensive use of sculptural slabs (casing slabs) carved from white limestone (often called Palnadu marble). Unlike the dome of Sanchi Stupa-1, which was originally plain, the dome and drum of the Amaravati Stupa were covered with elaborate relief sculptures depicting the life of Buddha and Jataka tales.
Key Takeaway:
Sanchi Stupa is characterized by its well-preserved Toranas and relatively plain hemispherical dome. Amaravati Stupa is distinguished by its Ayaka platforms (projecting platforms with pillars) and the rich sculptural casing covering its dome, though the main structure is now ruined.