A metal surface is illuminated by light of two different wavelengths 248 nm and 310 nm. The maximum speeds of the photoelectrons corresponding to these wavelengths are $$u_1$$ and $$u_2$$,respectively. If the ratio $$u_1 : u_2 = 2 : 1$$ and hc = 1240 eV nm, the work function of the metal is nearly

A

3.7 eV

B

3.2 eV

C

2.8 eV

D

2.5 eV