The correct option is Haryana and Delhi.
Explanation
A water divide (or watershed) is an elevated area, such as a mountain, plateau, or upland, that separates two distinct drainage basins. The divide between the Indus and the Ganga river systems determines whether water flows westwards into the Arabian Sea or eastwards into the Bay of Bengal.
Geographical Analysis:
- The water divide between the Indus and the Ganga systems is primarily located in the states/territories of Haryana and Delhi.
- Ambala (Haryana): This city is located on the crest of the water divide. It sits at an elevation slightly higher than the surrounding plains, directing the flow of the Sutlej and its tributaries towards the west (Indus system) and the Yamuna and its tributaries towards the east (Ganga system).
- Delhi Ridge: An extension of the Aravalli Range, the Delhi Ridge acts as a physical barrier in the semi-arid plains, reinforcing the separation between the two drainage basins.
Analysis of Other Options:
- Punjab: This state is predominantly part of the Indus drainage basin (drained by rivers like the Sutlej, Beas, and Ravi).
- Uttar Pradesh: This state lies entirely within the Ganga drainage basin.
- Himachal Pradesh: While rivers from both systems originate or flow through here, the distinct structural divide in the plains is defined by the Ambala-Delhi axis.
Key Takeaway: The Ambala water divide in Haryana and the Delhi Ridge form the crucial separation between the Indus River System (flowing into the Arabian Sea) and the Ganga River System (flowing into the Bay of Bengal).