If $x, v$ and a denote the displacement, the velocity and the acceleration of a particle executing simple harmonic motion of time period T, then, which of the following does not change with time ?

Question

( A ) $aT + 2 \pi v$
( B ) $\frac{aT}{x}$
( C ) $\frac{aT}{v}$
( D ) $a^2 T^2 + 4 \pi^2 v^2$