An ionic compound made up of atoms A and B has a face-centred cubic arrangement in which atoms A are at the corners and atoms B are at the face-centres. If one of the atoms is missing from the corner, what is the simplest formula of the compound?

Question

$\begin{array}{1 1}(A)\;A_6B_{23}&(B)\;A_7B_{27}\\(C)\;A_7B_{24}&(D)\;A_6B_{24}\end{array} $