Which one of the following graphs for a body moving along a straight line is possible?

Draw the $x-t$ graph for positive acceleration.

$A$ particle of mass $m$ is constrained to move on the $x$-axis. $A$ force $F$ acts on the particle. $F$ always points toward the position labeled $E$. For example,when the particle is to the left of $E$,$F$ points to the right. The magnitude of $F$ is a constant $F_0$ except at point $E$ where it is zero. The system is horizontal. $F$ is the net force acting on the particle. The particle is displaced a distance $A$ towards the left from the equilibrium position $E$ and released from rest at $t = 0$. The velocity-time graph of the particle is:

The position $x$ of a particle varies with time $t$ as $x = ct^2 + b$,where $c$ and $b$ are positive constants. Which of the following graphs is correct?

An object is moving with variable speed,then

$A$ particle shows a distance-time curve as shown in the figure. The maximum instantaneous velocity of the particle is around the point: