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 parallel but not 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 Y-values are the same for all groups. b There are differences in the average Y-values when comparing the groups. Your answer c Once we control for X, there are not differences in the average Y value when comparing the groups. d Once we control for X, there are some differences in the average Y value when comparing the groups