Under Semi-Infinite Boundary Conditions, for a Simple Electron Transfer Reaction $$\frac { \pi } { 2 }$$

Under semi-infinite boundary conditions, for a simple electron transfer reaction, the concentration oscillations and potential oscillations have a phase offset (in radians) of

A) $$\frac { \pi } { 2 }$$
B) $$\frac { - \pi } { 2 }$$
C) 0
D) $$\frac { \pm \pi } { 4 }$$