If the instantaneous velocity of a particle projected as shown in figure is given by  $\mathbf{v}=a\hat{\mathbf{i}}+(b-ct)\hat{\mathbf{j}}$. where a, b and c are positive constants, the range on the horizontal plane will be

• A

  2ab/c

• B

   ab/c

• C

   ac/b

• D

  a/2bc