Answer
$I = 0.255~kg~m^2$
Work Step by Step
We can find the angular acceleration of the wheel.
$\alpha = \frac{\omega}{t}$
$\alpha = \frac{(12.0~rev/s)(2\pi~rad/rev)}{2.00~s}$
$\alpha = (12.0~\pi)~rad/s^2$
We can find the moment of inertia of the wheel.
$\tau = I\alpha$
$I = \frac{\tau}{\alpha}$
$I = \frac{F~R}{(12.0~\pi)~rad/s^2}$
$I = \frac{(80.0~N)(0.120~m)}{(12.0~\pi)~rad/s^2}$
$I = 0.255~kg~m^2$