This graph shows the number of jars that are filled by machine a and machine b. which statement is true about the unit rates shown in the graph? a. the unit rate for a machine a is greater because the slope is less than the slope for machine for machine b. b. the unit rate for machine b is greater because the slope is less than the slope for machine a. c. the unit rate for machine a is greater because the slope is greater than the slope for machine b. d. the unit rate for machine b is greater because the slope is greater than the slope for machine a.