A particle moves in space along the path `z=ax^(3)+by^(2)` in such a way that `(dx)/(dt)=c=(dy)/(dt)` where `a,b` and `c` are constants. The acceleration of the particle is
A. `(6ac^(2)x+2bc^(2))hatk`
B. `(2ax^(2)+6by^(2))hatk`
C. `(4bc^(2)+3ac^(2))hatk`
D. `(bc^(2)x+2by)hatk`