It would be C. The golf ball has a greater average rate of change of 4.5 meters per second over the given interval, and that can be seen when we operate:
Golf ball:
[tex]r=\frac{32-14}{7-3}\Rightarrow r=\frac{9}{2}\Rightarrow r=4.5[/tex]Baseball:
[tex]r=\frac{15-6}{7-3}\Rightarrow r=\frac{9}{4}\Rightarrow r=2.25[/tex]