Why Correct: The Ganga forms the world's largest delta, the Sundarbans, where it splits into distributaries before entering the Bay of Bengal.
Distractor Analysis: Estuaries are partially enclosed coastal water bodies where rivers meet the sea with tidal mixing. Bird's foot estuaries feature elongated distributaries resembling a bird's foot, like the Mississippi Delta.
Takeaway: Major Indian rivers forming deltas include the Ganga-Brahmaputra, Godavari, Krishna, and Mahanadi, while Narmada and Tapti form estuaries.