Which of the following is/are correct for a diamond structure?

The correct option is D There are 8 atoms per unit cell.
In a diamond structure :
Carbon particles occupy half of tetrahedral voids and occupy fcc sites.
There are 8 atoms per unit cell.
The structure of diamond is identical to zinc blende $\left(ZnS\right)$ structure.
Here,
$\frac{\sqrt{3}a}{4}=2r_c$
Here,
$a$ is the edge cell length.
$r$ is the radius of carbon atom.