I would probably say 46 but I’m not entirely sure
Answer:

Step-by-step explanation:
Given that,
The frequency of x-rays, 
We need to find the wavelength for x-rays. The relation between wavelength, frequency and speed of light is given by :

So, the wavelength for x-rays is
.
Answer:B
Step-by-step explanation: It is wrong bruv
You can divide 84 and 144 and convert the answer to a fraction.
Correct me if I am wrong.