The inner planets—mercury, venus, earth, and mars—are believed to have been formed by masses of cold hydrogen and helium collisions with large galaxies the combining of asteroid-sized debris the explosion of supernovas

Repeated collisions of asteroid-sized debris

i think its control and coordinate because im pretty sure thats what tissue does and the joints are what control movement and then your skeletal/ bones provides portection. hope that .

the correct answer is b