Final answer:
The scale factor determines the change in area when the playground is expanded uniformly.
Step-by-step explanation:
The scale factor determines the change in area when the playground is expanded uniformly. The scale factor represents the ratio of the new dimensions to the original dimensions.
For example, if the scale factor is 2, it means that the new dimensions of the playground will be twice as long as the original dimensions. Therefore, the new area will be four times the original area (2 multiplied by 2 equals 4).
So, the correct answer is c) Scale factor.