A cyclist is moving with a speed of $6 ms^{-1}$, As he approaches a circular turn on the road of radius $120 \;m$ he applies brakes and reduces his speed at a constant rate of $0.4 \;ms^{-2}$. The magnitude of the net acceleration of the cyclist on the circular turn is
$\begin{array}{1 1} 0.5\; ms^{-2} \\ 1.0\;ms^{-2} \\ 2.0\;ms^{-2} \\ 4.0 \;ms^{-2} \end{array}$