A thin hoop is rotating about its central axis with an angular speed of $20ra\frac{d}{s}.$ The rotational inertia of the hoop about this axis is $28kg*m^2.$ A net torque is applied to the thin hoop, causing it to slow down and come to a stop. How much work is done by the net torque when the hoops angular speed changes from $20ra\frac{d}{s}$ to $0ra\frac{d}{s}?$

a$.-14$ J

b$.-280$ J

c$.-560$ J

d$.-5600$ J

e$.-11,200J$