The x - t graph of a particle performing simple harmonic motion is shown in the figure. The acceleration of the particle at t = 2 s is

Here, from the graph
Time period =8 s
Amplitude of oscillation =1 m
$\Rightarrow$Angular frequency $=\frac{2\pi }{8}=\frac{\pi }{4}{\mathrm{rads}}^{-1}$
$\Rightarrow$Maximum acceleration $=-\mathrm{A}{\omega }^2$
$=-\left(1\right)\cdot {\left(\frac{\pi }{4}\right)}^2=-\frac{{\pi }^2}{16}{\mathrm{ms}}^{-2}$