If the K， L， and M energy levels of Pt are 78000 eV， 12000 eV and 30000 eV， respectively， the wavelength of Ka line from Pt is（）

If the K， L， and M energy levels of Pt are 78000 eV， 12000 eV and 30000 eV， respectively， the wavelength of Ka line from Pt is（）
A.92.6 pm
B.43.6 pm
C.14.3 pm
D.18.6 pm
正确答案：18.6 pm