The correct answer is: a) River valleys.
Gujarat’s Paleolithic sites are primarily located along river valleys because these areas provide a number of advantages for early humans. River valleys offer a source of water, which is essential for life. They also provide a source of food, as fish and other animals can be found in rivers and streams. Additionally, river valleys are often fertile areas, which makes them ideal for agriculture.
Mountain ranges, coastal regions, and dense forests are all less likely to have Paleolithic sites because they offer fewer advantages for early humans. Mountain ranges can be difficult to travel through, and they often have harsh climates. Coastal regions can be dangerous due to the risk of storms and flooding. Dense forests can be difficult to navigate, and they can also be home to dangerous animals.
In conclusion, Gujarat’s Paleolithic sites are primarily located along river valleys because these areas offer a number of advantages for early humans.