At the mouth of which river system is the famous Sundarbans Delta located?

Correct answer: Ganga–Brahmaputra

A delta develops where a river slows near its mouth and deposits sediment through several distributaries. The Sundarbans form the world’s largest mangrove region and occupy the tidal delta at the head of the Bay of Bengal. This delta has been built mainly by the Ganga and Brahmaputra rivers, with the connected Meghna system and many distributaries also contributing sediment and water. Thus the most accurate school-level answer is the Ganga–Brahmaputra river system, option C. The Mahi–Sabarmati and Narmada–Tapi systems drain toward the western coast and do not create the Sundarbans. The Krishna–Cauvery system is associated with peninsular river deltas farther south. Therefore, the location and the process of sediment deposition both support option C.