When a beam of accelerated electrons collides with a target then continuous spectrum of X-rays is emitted. Which wavelength will be absent in the spectrum of X-ray emitted from X-ray tube operated at 40 kV ?

Options

A. `1.5 overset@A`
B. `0.5 overset@A`
C. `0.25 overset@A`
D. `1 overset@A`.