Answer:
m
Explanation:
Given that the wavelengths for X-rays with frequency

To find the wavelengths for the given X-rays:
The distance between two peaks in a wave is called the wavelength.
The value of wavelength is equal to the wave velocity divided by the frequency.
That is written by



(by using the property
)
(by using the property
)

m (by using the property
)
∴
m