If a voltage to an X-ray tube is increased to 1.5 times the minimum wavelength `(lamda_(min))` of an X-ray continuous spectrum shifts by `Delta lamda = 26` pm. The initial voltage applied to the tube is
A. `~~ 10 kV`
B. `~~ 16 kV`
C. `~~ 50 kV`
D. `~~ 75kV`