A continuity equation for two dimensional compressible flow is given by:

• A. \(\frac{{\partial u}}{{\partial x}}\; + \;\frac{{\partial v}}{{\partial x}}\left( {\rho uv} \right)\; = 0\)
• B. \(u\frac{{\partial u}}{{\partial x}}\; + v\frac{{\partial v}}{{\partial x}}\; = 0 \)
• C. \(\frac{{\partial \left( {\rho u} \right)}}{{\partial x}}\; + \;\frac{{\partial \left( {\rho v} \right)}}{{\partial y}} = 0\)
• D. \(\frac{{\partial u}}{{\partial x}}\; + \;\frac{{\partial v}}{{\partial x}}\; = 0 \)