A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is Φi yi P = Yi xi fi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of$

• A. temperature only.
• B. temperature and pressure only.
• C. temperature, pressure and liquid composition xi only.
• D. temperature, pressure, liquid composition xi and vapour composition yi.