Which of the following statements concerning a face- centered cubic unit cell and the corresponding lattice, made up of identical atoms, is incorrect? A. If the atoms have radius r, then the length of the cube edge is √8 times f. B. The close-packed direction lies along the face diagonal of the unit cell. C. The coordination number of the atoms in the lattice is V8. D. There are four atoms per unit cell in this type of packing. E. All statements are correct.