Consider a model of finite control volume (volume V and surface area) moving along the flow with elemental volume dV, vector elemental surface area d ( vec{S} ), density and flow velocity ( vec{V} ). What is the time rate of change of mass inside the control volume?

• A. ( iiint_V rho dV )
• B. ( frac{ partial}{ partial t} iiint_V rho dV )
• C. ( frac{D}{Dt} iiint_V rho dV )
• D. dV