A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration `a_(c)` is varying with time t as `a_(c) = k^(2)rt^(2)`, where k is a constant. The power delivered to the particle by the forces acting on it is :
A. `2 pimk^(2)r^(2)t`
B. `mk^(2)r^(2)t`
C. `1/3 mk^(4)r^(2)t^(5)`
D. 0