Based on the descriptions of wet snow, dry snow, and medium-wet snow, gracie used this characteristic to classify the types of snow: select one:
a. coloration
b. size and shape
c. moisture levels
d. method of formation

Types of snow are going to be classified according to their C. moisture levels.
Dry snow has the least amount of moisture in it, medium-wet snow has a moderate amount, and wet snow has a lot of moisture. This is the criterion according to which the types of snow are going to be classified - it has nothing to do with coloration, size and shape, and the method of formation, but rather with their moisture.