Option b is the correct answer. Megaliths are large stones that have been used to construct prehistoric structures or monuments, often for funerary purposes. Some types of megalithic structures are dolmens, cists, menhirs, and stone circles, which are usually associated with burials or tombs Megaliths have been found in many parts of the world, including India, where they date back to the Neolithic and Early Iron Age periods. Important Tips Megaliths are found across the whole of India, but they are more common in central, southern and eastern India. Some of the most important megalithic sites in India are: Adichanallur in Tamil Nadu, where more than 160 urns containing human skeletons and artefacts have been excavated. Thrissur in Kerala, where a large number of dolmens and menhirs have been discovered. Nagarjunakonda in Andhra Pradesh, where a complex of megalithic tombs and cairns dating back to the 1st millennium BCE have been found. Jaunapani in Maharashtra, where a group of 400 megaliths arranged in circles and rows have been identified. Maski in Karnataka, where a megalithic site with rock paintings and inscriptions has been located. Brahmagiri in Karnataka, where several megalithic burials and stone alignments have been excavated. Piklihal in Karnataka, where a megalithic site with pottery, iron tools and beads has been explored. Hallur in Karnataka, where a megalithic site with multiple types of burials and artefacts has been studied.