A point mass oscillates along the $x$-axis according to the law $x=x_0 \cos (\omega t - \pi/4)$. If the acceleration of the particle is written as : <br> $a = A \cos (\omega t + \delta)$, then :

Question

( A ) $A = x_0 \omega^2, \delta = \pi/4$
( B ) $A = x_0 \omega^2, \delta = -\pi/4$
( C ) $A = x_0 , \delta = -\pi/4$
( D ) $A = x_0 \omega^2, \delta = 3\pi/4$