Two particles of masses `m` and `2m` are placed at separation `L`. Find the `M.I.` about an axis passing through the center of mass and perpendicular to the line joining the point masses.
A. `(2mr^(2))/(3)`
B. `(mr^(2))/(2)`
C. `(mr^(2))/(4)`
D. `(3mr^(2))/(4)`
