[单选题]
An object moves in a circular pvyes +o:wt;7rath of ra9 c9oad ljw+2hdius $2 \, m$ with angular displacement of $\frac {π} {2}$ rad in $5 \, s$
What is the linear speed of the object?
A. $\frac{π}{20} \, m \, s^{-1}$
B. $\frac{π}{10} \, m \, s^{-1}$
C. $\frac{π}{5} \, m \, s^{-1}$
D. $\frac{π}{5} \, m \, s^{-1}$
