Which of the following velocity-time graphs is physically not possible?

Given below are two statements:
Statement $I:$ Area under velocity-time graph gives the displacement of the body in a given time.
Statement $II:$ Area under acceleration-time graph is equal to the change in velocity in the given time.
In the light of given statements,choose the correct answer from the options given below.

The displacement of a particle as a function of time is shown in the figure. The figure shows that

The position $(x)$ of a particle moving along the $x$-axis varies with time $(t)$ as shown in the figure. The average acceleration of the particle in the time interval $t=0$ to $t=8 \, s$ is ........... $m/s^2$.

The position of a particle moving along the $y-$ axis is given as $y = 3t^2 - t^3$,where $y$ is in $m$ and $t$ is in $s$. The time when the particle attains the maximum positive position will be ........ $s$.

Among the following,the velocity $(v)$ - time $(t)$ graph representing the motion of a vertically projected body is