The density of a circular disc is given as `sigma=rho_(0)x ` where `\'x\'` is the distance from the centre. Its moment of inertia about an axis perpendicular to its plane and passing through its edge is: (A) `15/16rho_(0)piR^(5)` (B) `16/15rho_(0)piR^(5)` (C) `6/5rho_(0)piR^(5)` (D) `5/6rho_(0)piR^(5)`