Nakki Lake is situated at Mount Abu in Sirohi district at an elevation of about 1,200 meters, making it the highest lake in Rajasthan.

• Alwar: Known for Siliserh Lake, not Nakki Lake.
• Ajmer: Famous for Ana Sagar and Foy Sagar lakes.
• Sirohi: Nakki Lake is situated in Mount Abu (Sirohi), famous for Toad Rock and Nun Rock.
• Udaipur: Known as the 'City of Lakes' with Pichola and Fateh Sagar lakes.

The Chambal River is famous worldwide for extensive gully erosion creating deep ravines and badland topography (Bihad) across eastern Rajasthan.

• Luni: Major ephemeral river system of western arid Rajasthan.
• Mahi: Flows through southern Rajasthan forming the Chappan plains.
• Chambal: Renowned for intense ravine formation and badland topography in Kota, Bundi, Sawai Madhopur, Karauli, and Dholpur.
• Banas: Creates an undulating alluvial plain (Piedmont plain), not badlands.

Mahi and Sabarmati empty into the Gulf of Khambhat, and Luni drains into the Rann of Kutch (all part of the Arabian Sea drainage), whereas Chambal flows to the Yamuna and drains into the Bay of Bengal.

• and (B): Incorrect because Chambal drains into the Bay of Bengal.
• , (B) and (C): Includes Chambal, which is part of the Bay of Bengal drainage.
• , (B) and (D): Includes Chambal, which is incorrect.
• , (C) and (D): Mahi, Sabarmati, and Luni all belong to the Arabian Sea drainage system of Rajasthan.