# In a compound atoms of element Y form ccp lattice and those of element X occupy ${\large\frac{2}{3}}^{rd}$ of tetrahedral voids. The formula of the compound will be
$(a)\;X_4Y_3\qquad(b)\;X_2Y_3\qquad(c)\;X_2Y\qquad(d)\;X_3Y_4$