The work function of a metal is `4.2 eV`. If radiation of `2000 Ã` fall on the metal then the kinetic energy of the fastest photoelectron is

Options

A. `1.6 xx 10^(-19)J`
B. `16 xx 10^(10) J`
C. `3.2 xx 10^(-19) J`
D. `6.4 xx 10^(-10)J`

Answer

C