During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,
-
A.
the litmus turns blue but no gas is evolved -
B.
the litmus turns blue and oxygen is evolved -
C.
the litmus turns blue and hydrogen is evolved -
D.
the litmus turns red and oxygen is evolved -
E.
the litmus turns red and then becomes colourless