Step 1: Understanding the Concept:
The question requires knowledge of the various historical and official terms used to refer to the communities now listed as Scheduled Castes.
Step 2: Detailed Explanation:
- (A) Depressed Classes: This was a widely used term in British India, particularly in official documents and by leaders like B.R. Ambedkar, to refer to the untouchable castes.
- (C) Untouchables: This was the common, though pejorative, term used to describe these communities due to the practice of untouchability.
- (B) Exterior Castes: This term was used by some British census commissioners, like J.H. Hutton in the 1931 census, to classify castes that were considered outside the pale of the Hindu caste system.
- (D) Interior Castes: This is not a standard or recognized term used to describe Scheduled Castes. The terminology often emphasized their exclusion ('exterior', 'outcaste'), not their inclusion ('interior').
Step 3: Final Answer:
'Interior castes' is not a standard expression used for scheduled castes.