On what basis are Bhangar and Khadar differentiated in Himalayan river plains?

Correct answer: Age and position of alluvial deposits

The direct answer is A: Bhangar and Khadar are differentiated by the age and position of alluvial deposits. Rivers spread sediments over their floodplains. Older alluvium, called Bhangar, generally lies on slightly higher terraces away from the active floodplain and is less frequently renewed by floods. Newer alluvium, called Khadar, lies in the lower active floodplain and is renewed more often by fresh deposits during floods. Option A is correct because it includes both time and location. Option B is wrong because sea-tide height is not the basis for this inland plain classification. Option C is wrong because glacier thickness belongs to glacial features, not to the distinction between these alluvial surfaces. Option D is wrong because volcanic ash colour is not the defining criterion. A small caution is useful: local soil colour or fertility may vary, but the core examination distinction remains older, higher Bhangar versus newer, lower Khadar. Memory cue: Bhangar is old and above; Khadar is young and near the active river.