Light of wavelength 4000 Å falls on a photosensitive metal and a negative 2V potential stops the emitted electrons. The work function of the material (in eV) is approximately \[(h=6.6\times {{10}^{-34}}Js,\ \ e=1.6\times {{10}^{-19}}C,\ \ c=3\times {{10}^{8}}m{{s}^{-1}})\]

• A. 1.1
• B. 2
• C. 2.2
• D. 3.1