A 5 watt source emits monochromatic light of wavelength 5000 Å. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0m, the number of photo electrons liberated will :

Question

( A ) be reduced by a factor of 4
( B ) be reduced by a factor of 16
( C ) be reduced by a factor of 8
( D ) be reduced by a factor of 2