The correct answer is (b) Khasi Hills.
The Khasi Hills are a mountain range in the state of Meghalaya, India. The hills are made of limestone, which is a type of rock that is easily dissolved by water. Over time, the water has eroded the limestone, creating caves. The caves in the Khasi Hills are some of the largest and most beautiful in the world. They are a popular tourist destination.
The Garo Hills are a mountain range in the state of Meghalaya, India. The hills are made of sandstone, which is a type of rock that is not as easily dissolved by water. As a result, there are no caves in the Garo Hills.
The Jaintia Hills are a mountain range in the state of Meghalaya, India. The hills are made of limestone, like the Khasi Hills. However, the caves in the Jaintia Hills are not as well-known as the caves in the Khasi Hills.
The Brahmaputra Valley is a large plain in the state of Assam, India. The valley is made of alluvial soil, which is a type of soil that is deposited by rivers. As a result, there are no caves in the Brahmaputra Valley.