which is a way to express concentration of a solution?\nparts per billion\nmoles\nmolar mass\nforce per…

Answer:

A. parts per billion

Brief Explanations:

Parts - per - billion (ppb) is a unit for expressing low - level concentrations in a solution. Moles measure amount of substance, molar mass is mass per mole of a substance, and force per square meter is pressure, not related to solution concentration.