A metal surface of area 1 cm² is uniformly illuminated by light of wavelength 400 nm and total power 5 mW. Assuming that every incident photon ejects one electron (100 % quantum efficiency) and that the frequency of light is above the threshold, what is the approximate saturation current obtained?
a) 0.16mA
b) 16mA
c) 1.6mA
d) 0.016mA