What is the difference between soft and hard $X-$rays?

Consider the following two statements $A$ and $B$ and identify the correct choice in the given answer.
$A:$ The characteristic $X-$ray spectrum depends on the nature of the material of the target.
$B:$ The short wavelength limit of the continuous $X-$ray spectrum varies inversely with the potential difference applied to the $X-$ray tube.

The wavelength of $K_\alpha$ $X$-rays produced in an $X$-ray tube is $0.76 \ \mathring{A}$. The atomic number of the anode material is:

The $X$-ray beam coming from the $X$-ray tube will be:

What determines the hardness of the $X-$rays obtained from the Coolidge tube?

An $X$-ray has a wavelength of $0.010 \mathring{A}$. Its momentum is