The graph illustrates how the velocity of a ball changes with time from the instant it is struck vertically upwards from the ground. What is the displacement of the ball from the ground after a time of $3.0\,\text{s}$?
- A$15\,\text{m}$
- B$25\,\text{m}$
- C$30\,\text{m}$
- D$45\,\text{m}$