This relief sculpture is an example of a
a. high relief
c. freestanding relief
b. low relief
d. sunken relief

There should have been a picture of the relief sculpture. I'll just define the choices.

Here are the three types of relief sculpture:

1) High relief is a sculpture whose form extends at least halfway out of the back ground. 

2) Low relief is a sculpture whose form projects only slightly from its background.

3) Sunken relief is a sculpture whose carvings are sunk below the level of the surrounding surface. 

A  documentary film  is a nonfictional motion picture intended to document some aspect of reality, primarily for the purposes of instruction, education, or maintaining a historical record.example:     20,000 days on earth