Given radiation has $14.4\, keV$ energy, so it is within the energy range for X-rays which is between $100\, eV$ to $100\, keV$.
The wavelength of given radiation,
$\lambda=\frac{h c}{E}$ joule $=\frac{6.64 \times 10^{-34} \times 3 \times 10^{8}}{14.4 \times 10^{3} \times 1.6 \times 10^{-19}}$ volt
$=0.86\,\mathring{A}$
X- rays have wavelength range between $0.1\, \,\mathring{A}$ to $1\,\mathring{A}$.