The correct answer is - That some force lifted the rocks from the water.
The fact that there's sedimentary rocks on the tops of the mountains is an evidence that there has been some force that managed to lift upwards parts of the seafloor. Taking into consideration how slowly this force manages to lift up parts of the Earth, we can easily assume that the Earth is very old. The amount of time that is needed for a part of the seafloor to be lifted few thousand meters upwards is counted in tens of millions of years, thus giving us evidence that the Earth has been around for a very long time.
The skeletal system does not digest. That is the job of the digestive system. Hope this helps!
Plate movement impacts the folding of this layer.
