Which of the following compounds represents 2,2,3-trimethylhexane?

The substance in choice C is 2,2,3-trimethyl hexane. It consists of ${\mathrm{CH}}_3\mathrm{C}{\left({\mathrm{CH}}_3\right)}_2\mathrm{CH}\left({\mathrm{CH}}_3\right){\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_3$. The parent hydrocarbon has six carbon atoms in it. It is therefore hexane. On the second, second, and third carbon atoms, there are three methyl groups as substituents.