Which of the Following Statements Concerning a Face-Centered Cubic Unit $\sqrt 8$

Which of the following statements concerning a face-centered cubic unit cell and the corresponding lattice,made up of identical atoms,is incorrect?

A) The coordination number of the atoms in the lattice is 8.
B) The packing in this lattice is more efficient than for a body-centered cubic system.
C) If the atoms have radius r,then the length of the cube edge is $\sqrt 8$ $\times$ r.
D) There are four atoms per unit cell in this type of packing.
E) The packing efficiency in this lattice and hexagonal close packing are the same.