Which among the following is an incorrect match?

There are eight corner atoms, six face-centered atoms, and four more atoms inside the diamond cubic unit cell. The number of formula units per $\mathrm{CsCl}$ unit cell is two. A $\mathrm{NaCl}$ unit cell has four formula units. So, all the other options are correct apart from $\mathrm{Na}$, which is only an atom, so it cannot have two atoms in a unit cell, making it the incorrect match.