Which of the following is the correct cooling curve for an amorphous solid?

Which one of the following statements is correct?

Which of the following statements is correct?

Atoms of metals $x$,$y$,and $z$ form face-centred cubic $(fcc)$ unit cell of edge length $L_x$,body-centred cubic $(bcc)$ unit cell of edge length $L_y$,and simple cubic unit cell of edge length $L_z$,respectively. If $r_z = \frac{\sqrt{3}}{2} r_y$; $r_y = \frac{8}{\sqrt{3}} r_x$; $M_z = \frac{3}{2} M_y$ and $M_z = 3 M_x$,then the correct statement$(s)$ is (are) [Given: $M_x$,$M_y$,and $M_z$ are molar masses of metals $x$,$y$,and $z$,respectively. $r_x$,$r_y$,and $r_z$ are atomic radii of metals $x$,$y$,and $z$,respectively.]
$(A)$ Packing efficiency of unit cell of $x >$ Packing efficiency of unit cell of $y >$ Packing efficiency of unit cell of $z$
$(B)$ $L_y > L_z$
$(C)$ $L_x > L_y$
$(D)$ Density of $x >$ Density of $y$

In the given cooling curve,what is the crystallization temperature in $K$?

Calculate the number of atoms present in $1.625 \text{ g}$ of a metal that forms a $bcc$ unit cell structure. Given: $[\rho \times a^3 = 3.25 \times 10^{-22} \text{ g}]$.