$4.$ Ceramic compounds $AB$ and $AC$ both have the zinc blende crystal structure and are soluble in one another at all concentrations. Determine the concentration in weight percent of $AC$ that must be added to $AB$ to yield a unit cell edge length of $0\mathrm{.}5304nm.$ The densities of $AB$ and $AC$ are $4\mathrm{.}8\frac{g}{c}{m}^3$ and $4\mathrm{.}2\frac{g}{c}{m}^3,$ respectively. The atomic weights of $A,B,$ and $C$ are $30,80,$ and $60\frac{g}{m}ol,$ respectively.

a$)38$

b$)26$

c$)32$

d$)41$

e$)21$

f$)15$

g$)45$

Could you please solve it step by step in an explanatory way in a notebook. The second time I uploaded the question, they couldnt solve it correctly