Suppose we have a scatter plot where the X variable is on the x-axis, the Y variable is on the Y-axis, and the dots are color-coded by Groups. Suppose the trend lines for each of these groups are approximately equal to each other. What would this graph suggest? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a The average value of Y is different for different groups. b Once we control for X, there are differences in the average value of Y when comparing the groups. c The average value of Y is the same for all groups. d Once we control for X, there are not large differences in the average value of Y when comparing the groups