Explanation:

- Kolathunadu, Valluvanad, and Thekkumkoor were ancient kingdoms located in the state of Kerala, India. These regions were part of what is now called Central and Northern Kerala.

- Option 4: Kerala - This is the correct answer. These kingdoms were situated in the area that is now part of modern-day Kerala.

- Option 1: Karnataka - Although close to Kerala geographically, Karnataka was home to different ancient kingdoms like the Chalukyas and Hoysalas.

- Option 2: Gujarat - This state is located to the northwest of India, with its own distinct historical regions such as Saurashtra and Kutch.

- Option 3: Bihar - Located in northeastern India, Bihar had its own ancient kingdoms like Magadha and Mithila.