The amount of stretch of a hanging spring versus the mass attached to the bottom of the spring was measured for different masses. The results are shown in the table. mass (grams) stretch centimeters) 24 48 8 10 16 | 20 What is the constant of proportionality between the mass and the amount of stretch? O 0.5 centimeters per gram O 0.5 grams per centimeter squared O 2.0 centimeters per gram O 2.0 grams per centimeter squared