The correct answer is: a) Eastern Ghats.
The Eastern Ghats are a mountain range that runs along the eastern coast of India. They are a major source of rainfall for the region, and they are home to a variety of plant and animal life. The Eastern Ghats are also home to a number of archaeological sites, including some that date back to the Paleolithic period.
The Deccan Plateau is a large plateau that covers much of central and southern India. It is a relatively dry region, and it is not home to as many archaeological sites as the Eastern Ghats.
The Coastal plains are a narrow strip of land that runs along the eastern and western coasts of India. They are a relatively fertile region, and they are home to a number of major cities, including Chennai, Mumbai, and Kolkata. However, the Coastal plains are not as well-suited for archaeological research as the Eastern Ghats or the Deccan Plateau.
River valleys are another potential location for Paleolithic settlements. However, the rivers in India are often prone to flooding, which can damage or destroy archaeological sites. As a result, there are fewer Paleolithic sites found in river valleys than in other parts of India.