Final answer:
The pH below that represents the highest OH is pH = 13.96.
Step-by-step explanation:
The pH below that represents the highest OH is pH = 13.96. In the pH scale, values greater than 7 indicate basic solutions. Since pH measures the concentration of H3O+ ions, a higher pH means a lower concentration of H3O+ ions and therefore a higher concentration of OH- ions. Therefore, the highest pH among the given options would correspond to the highest concentration of OH- ions.