$($a$)$ Determine the closed$-$loop transfer function $T(s)=Y\frac{s}{R}(s).$

$($b$)$ Determine the steady$-$state error of the closedloop system response to a unit ramp input.

$($c$)$ Select a value for $K_a$ so that the steady$-$state error of the system response to a unit step input is zero.