The coefficients for the Fourier Cosine expansion of f on the interval $[0,\pi]$ are given.

${\rm a}_0 = 0$

${\rm a}_1 =0$

${\rm a}_2 =-{\frac{1}{3}}$

${\rm a}_3 =-1$

Which of the following is the graph of f on $[-\pi,\pi]$? ? A B C D