When a monochromatic point source of light is at a distance of 0.2 m from a photoelectric cell, the cut off voltage and the saturation current are respectively 0.6 V and 18.0 mA. If the same source is placed 0.6 m away from the photoelectric cell, then (JEE 1992)
a. the stopping potential will be 0.2 V
b. the stopping potential will be 0.6 V
c. the saturation current will be 6.0 mA
d. the saturation current will be 2.0 mA