The correct answer is: Any of the above.
Megalithic structures are found all over the world, and their purpose is often debated. In Meghalaya, they are believed to have been used for a variety of purposes, including burial, ceremonial, and astronomical purposes.
Burial sites: Megalithic structures are often found in cemeteries, and they are believed to have been used to bury the dead. Some megalithic structures are very large, and they may have been used to bury important people or leaders.
Ceremonial centers: Megalithic structures are also found near ancient temples and other religious sites. They are believed to have been used for religious ceremonies, such as sacrifices or rituals.
Astronomical markers: Some megalithic structures are aligned with the sun, moon, or stars. This suggests that they may have been used for astronomical purposes, such as tracking the seasons or predicting eclipses.
It is possible that megalithic structures in Meghalaya were used for all of these purposes. More research is needed to determine their exact purpose.