In a binary liquid system, the composition expressed as _______________ is independent of the temperature & pressure?

In a binary liquid system, the composition expressed as _______________ is independent of the temperature & pressure?

A. Kg of solute/kg of solvent
B. Kg-mole of solute/kg-mole of solvent
C. Kg-mole of solute/1000 kg of solvent
D. All A., B. & C.