In an experiment, a heated cup of coffee is removed from a heat source and then allowed to cool in a room at a constant temperature. The x-axis represents the time since the cup was removed from the heat source (minutes), and the y-axis represents the temperature (°F). The scatter plot shows the temperature, in degrees Fahrenheit (), of the coffee immediately after removal and at 10-minute intervals thereafter. During which of the following 10-minute intervals does the temperature decrease at the least average rate?
Between 0 and 10 minutes
Between 30 and 40 minutes
Between 70 and 80 minutes
Between 130 and 140 minutes
