For the same total mass of the following will have the largest moment of inertia an axis passing through the centre of mass and perpendicular to the plane of the body

MI of disk of radius $a$ about given axis is $m{a}^2/2$

MI of ring of radius $a$ about given axis is $m{a}^2$

MI of square of side $2a$ about given axis is $m{\left(2a\right)}^2/6=2m{a}^2/3$

MI of four rods forming square of side $2a$ about given axis is $4\times m{\left(2a\right)}^2/12+m{a}^2=4m{a}^2/3$

So among all options four rods forming square of side $2a$ has highest moment of inertia of $4m{a}^2/3$ about an axis passing through its center of mass and perpendicular to the plane of body.