If a particle starts its motion from x=-4m, then which one represents the a-t graph?
The first figure is the question figure, the second figure contains the answer, and the third one contains the other options.

Why are these the wrong answers?
If a particle starts its motion from x=-4m, then which one represents the a-t graph?
The first figure is the question figure, the second figure contains the answer, and the third one contains the other options.

Why are these the wrong answers?
HINT: In your figure--the one that has the velocity graph that is the question, what is the slope of the graph, first for $t$ in the interval $(0,2)$, then for $t$ in the interval $(2,4)$.
HINT 2: The slope of a line segment from say $[0,2]$ is always a constant i.e., it is the same at $1/2$ as it is at $3/2$.