The Sudarshan Lake, an important Mauryan-era reservoir, is located near which city?

The correct answer is: a) Vadodara.

Sudarshan Lake is an important Mauryan-era reservoir located near the city of Vadodara in Gujarat, India. It was built by the Mauryan emperor Ashoka in the 3rd century BCE. The lake is a major source of water for the city of Vadodara and the surrounding area. It is also a popular tourist destination.

The other options are incorrect because they are not located near the city of Vadodara. Junagadh is located in the Saurashtra region of Gujarat, Surat is located in the Surat district of Gujarat, and Rajkot is located in the Rajkot district of Gujarat.