For a simple cubic $(SC)$,body-centered cubic $(BCC)$,and face-centered cubic $(FCC)$ unit cell with edge length $a$,what is the ratio of the radii of the atoms present in them?

• A
  $\frac{a}{2} : \frac{\sqrt{3}a}{4} : \frac{a}{2\sqrt{2}}$
• B
  $\frac{a}{2} : \sqrt{3}a : \frac{a}{2\sqrt{2}}$
• C
  $\frac{a}{2} : \frac{\sqrt{3}}{2} : \frac{\sqrt{2}a}{2}$
• D
  $14 : \sqrt{3}a : \sqrt{2}a$