"regular geometric" means you're looking at a solid. In a molecular gas, you will have a particular shape, but it's randomly oriented and there's no "regularity" to its placment. Similarly with the molecular liquid. The aq salt is even worse -- the molecules no longer even have a geometric shape.
A regular geometric pattern (crystal) has to be the solid. You don't really need to know what pattern it forms, since the other three answers can't be the answer.Table sugar forms cubes as a solid, where the molecules are arranged in neat rows.
Only solids can create regular geometric patterns... CO2 is a gas, H2O is a liquid and Sodium Chloride doesn't count because it's dissolved in a solution...
