What is the formula to compute the moment of inertia of the rotor blade about center of rotation?

Ib= ( int _0 ^R frac {m}{r^2} )dr

Ib= ( int _0 ^R frac {m}{r^3} )dr

What is the formula to compute the moment of inertia of the rotor blad

1.	What is the formula to compute the moment of inertia of the rotor blade about center of rotation?
A.	I<sub>b</sub>= ( int _0 ^R )mr<sup>2</sup>dr
B.	I<sub>b</sub>= ( int _0 ^R )mr<sup>3</sup>dr
C.	I<sub>b</sub>= ( int _0 ^R frac {m}{r^2} )dr
D.	I<sub>b</sub>= ( int _0 ^R frac {m}{r^3} )dr
Answer» B. I<sub>b</sub>= ( int _0 ^R )mr<sup>3</sup>dr