Answer
Gaseous carbon dioxide is represented by the molecules of
\[\text{C}{{\text{O}}_{2}}\]
. Therefore, option (c) is correct.
Work Step by Step
The chemical reaction for the sublimation of dry ice is
\[\text{C}{{\text{O}}_{2}}(\text{s}) \to \text{C}{{\text{O}}_{2}}(\text{g})\]
Sublimation is a physical change, so the composition of dry ice will remain the same.
Option (c) represents the molecules of
\[\text{C}{{\text{O}}_{2}}\]
so it is the best representation.