Why this Question: Caves and Stupas of ancient India and their location and other geographical aspects is an important static topic. 

Ans) a 

Exp) Option a is correct. 

Option a is correct. The rock-cut caves of Ajanta lie in Waghora river valley near Ajanta village in the Aurangabad district of Maharashtra.  

Option b is incorrect. Sanchi lies in an upland plateau region just west of the Betwa River.  

Option c is incorrect. Pandu-lena caves is ancient rock-cut sculptures complex located at Gomai River.   

Pandu-leni cave is also known as Nasik Caves, Tirthankar Leni, Panch Pandav or Pandav Leni Jain cave.  

The “Pandavleni” name sometimes given to the Nasik Caves has nothing to do with the characters Pandavas, characters in the Mahabharata epic. 

Option d is incorrect. Amravati stupa is located in the gorges of Krishna river. 

Source:  https://govtgirlsekbalpur.com/Study_Materials/History/AJANTA_CAVE_PAINTINGS.pdf 

https://www.britannica.com/place/Sanchi-historical-site-India 

https://www.incredibleindia.org/content/incredible-india-v2/en/destinations/amaravati.html  

https://indianculture.gov.in/pandulena-cave-no-6-original-land-being-removed-0  

https://www.nativeplanet.com/travel-guide/pandavleni-caves-nashik-maharashtra-001671-pg1.html 

 Subject) History