Answer:
The most appropriate answer would be a skeleton system.
The main function of the cytoplasm of a cell is to support and hold the cell organelles at their position. In addition, it also helps in protecting the organelles from damage.
Similarly, the main function of a skeleton system of multicellular organism support and protect the internal organs of the body. In addition, it helps in locomotion.
For example, rib cage provides protection to lungs and heart, skull protects the brain from damage et cetera.