Deopahar in Golaghat district is known for:

Ruins of an ancient city
Rock-cut caves
Sculptures and inscriptions
Neolithic artifacts

Deopahar in Golaghat district is known for its rock-cut caves. The caves are located on a hilltop and are believed to have been built by the Ahoms, a dynasty that ruled Assam from the 13th to the 18th centuries. The caves are decorated with sculptures and inscriptions, and are a popular tourist destination.

Option (a), ruins of an ancient city, is incorrect because there is no evidence that there was ever an ancient city at Deopahar.

Option (b), rock-cut caves, is correct because the caves are the main attraction at Deopahar.

Option (c), sculptures and inscriptions, is also correct because the caves are decorated with sculptures and inscriptions.

Option (d), Neolithic artifacts, is incorrect because there is no evidence that Neolithic artifacts have been found at Deopahar.