What is concentration?

The concentration of a chemical substance expresses the amount of a substance present in a mixture.

Another definition is that concentration is the ratio of solute in a solution to either solvent or total solution. Concentration is usually expressed in terms of mass per unit volume.

In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration.

i think the answer would be b

answer; how far out of place which the object finished relative to the starting location;