In `CaF_(2)` type (fluorite structure) `Ca^(2+)` ions form W structure and `F^(-)` ions are present in all X voids. The coordination number of `Ca^(2=)` is Y and `F^(-)` is Z. W,X,Y and Z respectively are

Options

A. A-ccp, B-octahedral , C-8,D-4
B. A-bcc, B-tetrahedral , C-4,D-8
C. A-ccp , B-tetrahedral , C-8,D-4
D. A-ccp, B-octahedral , C-4,D-8

Answer

C

Explanation

`Ca^(2+)` ions form ccp structure while `F^-` ions are in all tetrahedral holes and coordination numbers are 8 and 4