A particle of mass M is moving in a circular path of radius 2m. Its speed depends on the distance covered by the particle from the hegining according to the relation c = ks, where k is a positive constant and s is the distance covered. The power of force acting on teh particle when the particle has covered half of the circular path will be :
A. `pi^(2)k^(2)M`
B. `2pi^(2)k^(3)M`
C. `4pi^(2)k^(3)M`
D. `8pi^(2)k^(2)M`