In a two-dimensional velocity field with velocities u and v along the x and y directions respectively, the convective acceleration along the x-direction is given by

• A.  \[u\frac{\partial u}{\partial x}+v\frac{\partial u}{\partial y}\]       
• B.  \[u\frac{\partial u}{\partial x}+v\frac{\partial u}{\partial y}\]
• C.  \[u\frac{\partial v}{\partial x}+v\frac{\partial u}{\partial y}\]                   
• D.  \[v\frac{\partial u}{\partial x}+u\frac{\partial u}{\partial y}\]