A circular disc A of radius r is made from an iron plate of thickness t and another circular disc B of radius 4r and thickness $\frac{\mathrm{t}}{4}$. The relation between moments of inertia ${\mathrm{I}}_{\mathrm{A}} and\hspace{0.17em}{\mathrm{I}}_{\mathrm{B}}$ and  about the same axis is:

• A

  ${\mathrm{I}}_{\mathrm{A}} > {\mathrm{I}}_{\mathrm{B}}$

• B

  ${\mathrm{I}}_{\mathrm{A}} = {\mathrm{I}}_{\mathrm{B}}$

• C

  ${\mathrm{I}}_{\mathrm{A}} < {\mathrm{I}}_{\mathrm{B}}$

• D

  depends on the actual values of t and r