In which mode of expression, the concentration of a solution remains independent of temperature?

Molality 

The concentration of a solution that remains independent of temperature is: (2) Molality.

Molality (m) is defined as the number of moles of solute dissolved in exactly 1 kilogram of solvent. Since molality is based on the mass of the solvent (which does not change with temperature), it remains constant regardless of temperature changes. The mass of the solvent is not affected by temperature variations, as opposed to volume (molarity) or volume fraction, which can change with temperature due to thermal expansion or contraction. Therefore, the molality of a solution remains constant at different temperatures as long as the amount of solute and solvent remain unchanged.