What is a pigment cells that change the color of an organism, allowing it to camouflage?

Many of these creatures have special pigment cells called chromatophores in their skin. By controlling the size of the cells they can vary their color and even create changing patterns. Chromatophores are connected to the nervous system, and their size is determined by muscular contractions.

c. movement because i took the test and it lets me review my answers

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.