Which way of representing a molecule best shows its three-dimensional shape?

The best way to show the three dimensional shape of a molecule is to use the space filling molecular model also called Calotte model.  Calotte model is a type of three dimensional molecular model where atoms are arranged in such a way that atoms are represented by coloured spheres which take into account the radii of the real atoms. This model help the students to grasp the manner in which atoms and bonds are arranged in chemical compounds. 

Ibelieve its a because an empirical formula usually has a ch in it your options are a or b