Starting from rest, a particle rotates in a circle of radius $R=\sqrt 2 m$ with an angular acceleration $a=\large\frac{\pi}{4}$$rad/s^2$. The magnitude of average velocity of particle over time when it rotates quarter circle is

Question

$$(a)\;1.5 m/s \quad (b)\;2 m/s \quad (c)\;1.25m/s \quad (d)\;1 m/s$$