Clusters are when data is very close together therefore graphs 2 and 3 have clusters. The data doesn’t seem to fit the regression line very well like figure 4.
Outliers in data or scatter plots are when values are very separated form each other therefore scatter plot 1 is the only one that has outliers. It has blue dots that are very separate from its regression line.
Figure four doesn’t fit any of the questions asked.
Hope this helps!