A metal surface illuminated by 8.5×1014 Hz light emits electrons whose maximum energy is 0.52 eV.The same surface illuminated by 12.0×1014 Hz light emits electrons whose maximum energy is 1.97 eV.The work function of the metal is（B ）。

A metal surface illuminated by 8.5×1014 Hz light emits electrons whose maximum energy is 0.52 eV.The same surface illuminated by 12.0×1014 Hz light emits electrons whose maximum energy is 1.97 eV.The work function of the metal is（B ）。
A.3.0 eV
B.12.4 eV
C.47.5 eV
D.7.2 eV
正确答案：3.0 eV