The correct answer is: C) Brahmagiri
Brahmagiri is a prehistoric site located in the Chitradurga district of Karnataka, India. It is known for its megalithic dolmens, which are stone structures that were used as tombs. The dolmens at Brahmagiri are dated to the Iron Age, and they are some of the earliest examples of megalithic architecture in India.
The other options are incorrect because they are not prehistoric sites known for their megalithic dolmens. Chandravalli is a prehistoric site located in the Bellary district of Karnataka, India. It is known for its megalithic burials, but it does not have any dolmens. Piklihal is a prehistoric site located in the Raichur district of Karnataka, India. It is known for its megalithic settlements, but it does not have any dolmens. Sannati is a prehistoric site located in the Gulbarga district of Karnataka, India. It is known for its Buddhist stupas, but it does not have any dolmens.
Megalithic dolmens are stone structures that were used as tombs. They are typically made up of two large stones that are placed upright and a capstone that is placed on top of them. The dolmens at Brahmagiri are dated to the Iron Age, and they are some of the earliest examples of megalithic architecture in India.
The dolmens at Brahmagiri are located on a hilltop overlooking the Tungabhadra River. They are arranged in a circle, and they are surrounded by a stone wall. The dolmens are made up of large granite stones, and they are covered in red ochre. The capstones of the dolmens are decorated with geometric designs.
The dolmens at Brahmagiri are a significant archaeological site. They provide evidence of the early Iron Age cultures in India. They also show the importance of megalithic architecture in these cultures.