Recent research has confirmed that stonehenge originally was a

a.  religious temple.

b.  war monument.

c.  royal graveyard.

d.  palace.

Built in several stages, Stonehenge began about 5,000 years ago as a simple earthwork enclosure where prehistoric people buried their cremated dead. The stone circle was erected in the centre of the monument in the late Neolithic period, around 2500 BC

the answer is backup

relief sculpture - images are set against a flat background.

a coin is a good example: the inscription, the date, and the figure are slightly raised above a flat surface. the ancient egyptians sometimes carved figures into a flat surface.  

pro: they take significantly less time to make and do not require as much tools or skills as free-standing

cons: not nearly as realistic, as it is not fully 3-d, and does not have the details that a free-standing one does.

freestanding sculptures (also called  carved in the round) are not attached to any  background.   they are 3-dimensional  and fully rendered.