A disc is rolling without slipping on a surface. The radius of the disc is $R$. At $t = 0$, the top most point on the disc is $A$ as shown in figure. When the disc completes half of its rotation, the displacement of point $A$ from its initial position is\\
(1) $2R$\\
(2) $R\sqrt{\left(\pi^2 + 4\right)}$\\
(3) $R\sqrt{\left(\pi^2 + 1\right)}$\\
(4) $2R\sqrt{\left(1 + 4\pi^2\right)}$