The expected diffraction angle for the first$-$order reflection from the $(111)$ set of planes

for nickel $($Ni$)$ when monochromatic radiation of wavelength $0\mathrm{.}1937$ nm is used, is

a$)56\mathrm{.}650$

b$)28\mathrm{.}320$

c$)35\mathrm{.}520$

d$)71\mathrm{.}0550$