A particle of mass m moves along a circular path of radius r with centripetal acceleration \[{{a}_{n}}\] changing with time t as \[{{a}_{n}}=k{{t}^{2}}\], where k is-a positive constant. The average power developed by all the forces acting on the particle during the first \[{{t}_{0}}\] seconds is

• A. \[mkr{{t}_{0}}\]
• B. \[\frac{mkr{{t}_{0}}^{2}}{2}\]
• C. \[\frac{mkr{{t}_{0}}^{{}}}{2}\]                     
• D. \[\frac{mkr{{t}_{0}}^{{}}}{4}\]