d
\(\begin{array}{l}
Give\,initial\,velocity\,u = 0\,and\,acceleration\\
is\,{\rm{constant}}\\
At\,time\,t\\
v = 0 + \,at\\
\Rightarrow \,v = \,at\\
Also\,X = 0\left( t \right) + \frac{1}{2}a{t^2}\\
\Rightarrow \,\,X = \frac{1}{2}a{t^2}\\
Graph\,\left( a \right),\,\left( b \right)\,and\,\left( d \right)\,are\,correct.
\end{array}\)
