Potassium Iodide (Chemical Formula: KI) Has a Face-Centred Cubic Structure $\lambda$

Multiple Choice

Potassium Iodide (chemical formula: KI) has a face-centred cubic structure (just like sodium chloride) .If the distance between crystal planes is d = 0.353 nm and X-rays of wavelength $\lambda$ = 0.093 4 nm are used, what is the smallest angle $\theta$ at which a diffraction maximum may be obtained?

A) 9.92 $\degree$
B) 7.60 $\degree$
C) 13.3 $\degree$
D) 15.5 $\degree$
E) 6.52 $\degree$