Which option correctly describes multi-basis study of the Northern Plains?

Correct answer: Formation, river system, local belts, regional plains and importance

The direct answer is A: formation, river system, local belts, regional plains and importance. A multi-basis study means understanding a landform from more than one angle. First, study how the Northern Plains were formed by the deposition of alluvium brought by rivers. Next, study the major river systems and their deposits. Then examine local belts such as Bhabar, Terai, Bhangar and Khadar, followed by regional divisions such as the Punjab Plain and Ganga-Brahmaputra Plain. Finally, consider their importance for fertile agriculture, dense settlement, transport and industry. Option A is correct because it includes physical origin, drainage, subdivisions, regional pattern and human importance. Option B is wrong because sea depth is not the main basis for studying an inland alluvial plain. Option C is wrong because Himalayan peaks are a different physical division and do not explain the Northern Plains. Option D is wrong because the number of islands is unrelated to the formation and characteristics of these plains. The exam lesson is to avoid a one-clue answer when the question asks for a broad study framework.