Gandikota canyon of South India was created by which one of the following rivers?

The correct option is Pennar.

Explanation:
The Gandikota canyon, popularly known as the "Grand Canyon of India," is a stunning gorge formed by the Pennar River. It is located in the Kadapa district of Andhra Pradesh, South India.
Over millions of years, the Pennar River cut through the Erramala hills of red sandstone, carving out a deep and spectacular canyon that surrounds the historical Gandikota Fort. This natural geological formation showcases beautiful, steep rock formations and is a major tourist attraction in Andhra Pradesh.

Let us briefly look at the other rivers mentioned in the options to understand why they are not correct:
• Cauvery: This river flows through Karnataka and Tamil Nadu, and is famous for gorges like Mekedatu, but not the Gandikota canyon.
• Manjira: A tributary of the Godavari River, flowing primarily through Maharashtra, Karnataka, and Telangana.
• Tungabhadra: A major tributary of the Krishna River, flowing through Karnataka and Andhra Pradesh, known for its historical association with the Vijayanagara Empire ruins at Hampi.