Concentration: in simple terms, we can say that this is a measure of a solute dissolved in a particular amount of a solvent or of a solution.
We start analyzing these options:
Molarity can be defined as the moles of a solute per liter of a solution.
This is a concentration measurement.
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% by mass can be defined as the mass of a solute per 100 grams of a solution.
It is also a concentration.
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Relative saturation: the ratio of the mass of water vapor present to the mass that would be present if the air were saturated at the same conditions of temperature and pressure.
Answer: Molarity and % by mass