A time-independent surface current with density K flows in the x-y plane from infinity to the point

Question:

A time-independent surface current with density K flows in the x-y plane from infinity to the point r = 0 in a radially symmetric manner. As a result, charge accumulates at r = 0 at the rate dq/dt = I.
(a) Find the displacement current.
(b) Find the total magnetic field everywhere.