Question $7\mathrm{.}22-$ A flywheel weighs $1,000-lb$ and its diameter is $18-in.$ Assuming that the mass is well$-$distributed, its mass moment of inertia about x $-$axis is most nearly:

A$.0\mathrm{.}25f{t}^4$

B$.250lb-f{t}^4$

C$.2,170$ slugs $-f{t}^2$

D$.8,050$ slugs $-f{t}^2$