The Use of Ion-Selective Phases in Potentiometric Measurements Is Based

The use of ion-selective phases in potentiometric measurements is based on the potential that develops:

A) across the ion-selective phase once the ion has been captured in the ion-selective phase
B) after the ion passes through the ion-selective phase into the internal filling solution
C) across the liquid junction located between the tip of the reference electrode and the solution being measured
D) at the Ag/AgCl interface of the reference electrode