Pick the wrong statement of the following.

• A

  Photoelectric current increases with increase in accelerating potential until it becomes maximum value.

• B

  High voltage spark passed across electrodes in a discharge tube if they are illuminated by ultraviolet light.

• C

  To study the effect of potential on photo-electric current, we first maintain collector at positive potential with respect to emitter.

• D

  The maximum negative potential given to collector for which photoelectric current becomes zero is  called stopping potential.