Consider a uniform wire of mass $M$ and length $L$. It is bent into a semicircle. Its moment of inertia about a line perpendicular to the plane of the wire passing through the centre is:

• A
  $\frac{1}{4} \frac{ML^2}{\pi^2}$
• B
  $\frac{2}{5} \frac{ML^2}{\pi^2}$
• C
  $\frac{ML^2}{\pi^2}$
• D
  $\frac{1}{2} \frac{ML^2}{\pi^2}$