Expand the substantial derivative Dρ/Dt.

• A. \(\frac{D\rho}{Dt}=\frac{d\rho}{dt}+u \frac{d\rho}{dx}+v\frac{d\rho}{dy}+w\frac{d\rho}{dz}\)
• B. \(\frac{D\rho}{Dt}=\frac{\partial\rho}{\partial t}+u \frac{d\rho}{dy}+v\frac{d\rho}{dz}+w\frac{d\rho}{dx}\)
• C. \(\frac{D\rho}{Dt}=\frac{d\rho}{dz}+u\frac{\partial \rho}{\partial y}+v\frac{\partial \rho}{\partial z}+w \frac{\partial \rho}{\partial t}\)
• D. \(\frac{D\rho}{Dt}=\frac{\partial \rho}{\partial t}+u\frac{\partial \rho}{\partial x}+v\frac{\partial \rho}{\partial y}+w \frac{\partial \rho}{\partial z}\)