Explanation:

Let’s break it down:

- The Maharana Pratap Sagar reservoir, also known as Pong Dam, is on the Beas River in Himachal Pradesh.

- Here’s how your options stack up:

- Option 1: Ukai Dam

- That’s on the Tapi River in Gujarat, not Beas.

- Option 2: Tehri Dam

- That’s in Uttarakhand, built on the Bhagirathi river.

- Option 3: Polly Dam

- This isn’t a known dam; sounds like a misdirect or typo.

- Option 4: Dharoi Dam

- That’s on the Sabarmati River, again in Gujarat.

- The correct answer is actually Pong Dam (Maharana Pratap Sagar), but it’s not in your options. None of these names match. Out of the list, none are correct for the Beas River reservoir. If you had to pick based on the actual correct information:

- The dam is popularly called Pong Dam.

- None of the provided options fit, but definitely not Polly Dam.

So, that’s the real story here. When in doubt, remember: Pong Dam = Maharana Pratap Sagar on Beas River.