Correct answer is (c) 5.25kgm^2
For explanation I would say: Moment of inertia about an axis perpendicular to length and passing through COM is equal to MI^2/12. To find I about given axis, we use parallel axis theorem,
I = ICOM + ma^2, where a is the distance between the axis and m is mass of the body.
I = MI^2/12 + Ma^2
= 1*36/12 + 1*2.25
= 3 + 2.25 = 5.25kgm^2.