Consider the discretized form of an equation given by \(\frac{\partial(\rho u\phi)}{\partial x}=-a(\phi_c-\phi_u)+b(\phi_d-\phi_c).\) For this numerical scheme to be TVD, what is the condition?(Note: Φu, Φc and Φd are the flow variables at the far upwind, upwind and downwind schemes).

• A. a≥0;b≥0;0≤a+b≤1
• B. a≥0;b≤0;0≤a+b≤1
• C. .\) For this numerical scheme to be TVD, what is the condition?(Note: Φu, Φc and Φd are the flow variables at the far upwind, upwind and downwind schemes).a) a≥0;b≥0;0≤a+b≤1b) a≥0;b≤0;0≤a+b≤1c) a≥0;b≥0;0≤a-b≤1
• D. a≥0;≤0;0≤a-b≤1