A quality control manager is inspecting four digital scales to see if they accurately reflect a weight of 0 ounces. The table shows the weight displayed on four empty scales. Empty Scale Weight Displays Scale 1 –1 ounce Scale 2 –2 ounces Scale 3 0 ounces Scale 4 –1 ounce What is the average error in the scale displays? A. –4 ounces B. –1 ounces C. 0 ounces D. 1 ounce