The article states:

On this show, the "fighting" was friendly but fierce. Teams had to build giant 3D artwork out of flowers and plants. Their sculptures included a 10-foot (3-meter) seahorse statue and a full-size model of a fairytale house.
Which words from the passage help you understand the meaning of the word sculptures?
A.flowers and plants
B.seahorse statue
C.friendly but fierce
D.on this show

The word "sculptures" refers to the giant 3D artworks built out of flowers and plants, as mentioned in option A.