A block $A$ of mass $m$ connected with a spring of force constant $k$ is executing SHM. The position $(x)$ and time $(t)$ equation of the block is $x=x_{0}+a \sin \omega t$. An identical block $B$ moving towards negative $x$-axis with velocity $v_{0}$ collides elastically with block $A$ at time $t=0$. Then
(A) Displacement time equation of $A$ after collision will be $x=x_{0}-v_{0} \sqrt{\frac{m}{k}} \sin \omega t$.
(B) Displacement time equation of $A$ after collision will be $x=x_{0}+v_{0} \sqrt{\frac{m}{k}} \sin \omega t$.
(C) Velocity of $B$ just after collision will be $a \omega$ towards positive $x$-direction.
(D) Velocity of $B$ just after collision will be $v_{0}$ towards positive $x$-direction.