Which of the following substances is a non-electrolyte?
A) [tex]\mathrm{NH}_4 \mathrm{NO}_3[/tex]
B) [tex]\mathrm{H}_3 \mathrm{PO}_4[/tex]
C) [tex]\mathrm{CH}_3 \mathrm{COOH}[/tex]
D) [tex]\mathrm{CaCl}_2[/tex]
E) cyclohexane [tex]\left(\mathrm{C}_6 \mathrm{H}_{12}\right)[/tex]