Which residual plot shows that the line of best fit is a good model?
A
A graph shows both axes unnumbered. Points show a downward trend.
B
A graph shows both axes unnumbered. Points show an upward then downward trend.
C
A graph shows both axes unnumbered. Points are scattered all over the graph. 
D
A graph shows both axes unnumbered. Points show a downward then upward trend. 