A student drew atomic models of four elements. Based on these drawings, which element is the least reactive?

A.
Neon, because it has two energy levels with eight electrons in the second level

B.
Chlorine, because it has three energy levels with seven electrons in the third level

C.
Gallium, because it has four energy levels with three electrons in the fourth level

D.
Tin, because it has five energy levels with four electrons in the fifth level